QuantumG's Blog

A Little Ray Of Sunshine

2011-12-16T10:26:00.000+10:00

Well it seems someone managed to sneak into the commercial crew office at NASA and smack them with a clue stick. Today they announced that there will be a third round of Space Act Agreements to maximize the $406M awarded for the program in FY2012.

That's the way NASA sees it anyway. What this actually means is that the partners which are selected - and we're told they desire to select more than one - will be free to pursue their own goals without the burdensome oversight of the growing commercial crew office. It means that companies like SpaceX can design their Dragon capsule to service both NASA's needs and the needs of other companies like the recently announced Statolaunch without asking Mother May I?

I can't wait to see the milestones.

The Case Against SpaceX

2011-11-21T14:21:00.001+10:00

As an advocate of commercial spaceflight I can understand why many find it difficult to write objectively about SpaceX - which is arguably the poster child of this nascent industry. As a result, the majority of negative commentary about our darling comes from a horrible "journalist" like Andy Pasztor at The Wall Street Journal or a traditional aerospace mouth-piece like Loren Thompson at Forbes. An occasional coherent comment on a blog or space forum may be accepted by the space community as containing a nugget of truth, but these are easily filed in the don't-think-too-hard-about basket and forgotten. I've taken to thinking about the criticism I have heard, and after some long and rather arduous discussion with these critics I've processed it through what I hope are reasonable and constructive filtering. Here's the finished package.

The Circuitous Route To Reuse

Since SpaceX first announced the Falcon 9 they have claimed it is designed to be reusable, but they've yet to demonstrate how. For a number of years the answer has, apparently, been parachutes. Both the successful flights of the Falcon 9 have carried them and for a while we were told they had been deployed. Gwynne Shotwell, speaking at the Space Access conference this year was quoted "We have recovered pieces of the first stages." They were breaking up during re-entry, not giving the parachutes time to deploy.

Most recently, SpaceX has announced with fanfare the new overall approach with pretty graphics and a funky soundtrack. Clearly, they are still a long way away from a working vehicle. I asked Gary Hudson on The Space Show to provide us an educated guess at how fast the Falcon 9 may be going at first stage separation, and at what altitude - the kind of trivial information required to even visualize how such a vehicle could function. He declined.

While it is certainly true that SpaceX's engineers have a lot more information and no doubt have some idea how it is supposed to work, I find it more than a little disconcerting that arguably one of the most seasoned RLV veterans around today isn't able to speculate. At the same time, a new test program dubbed Grasshopper was announced to test vertical takeoff, vertical landing (VTVL) which is a critical part of the new non-parachute approach to reuse.

If that sounds familiar, it should. A subscale VTVL demonstrator has been considered the starting point for this kind of RLV ever since the DC-X program back in the early 1990s. More recently, Armadillo Aerospace and Masten Space Systems have been following this path, with considerably less money to play with. It's 2011 and it seems like SpaceX is starting all over again with reuse.

The Funding Crunch

There's another pathway to reuse: put wings on it. So far, we haven't seen any indication that SpaceX is pursuing that route but, then again, we saw no indication they were pursing VTVL a year ago either. A regularly advocated way to maintain revenue while pursing this route is to woo suborbital markets such as scientific research and tourism. This approach is best exemplified by XCOR and, to a lesser extent Virgin Galactic (as they still seem to have no orbital aspirations). So far, there is no indication that SpaceX is doing that either, but who knows what the future might bring. If the current suborbital providers are successful it may boost investor confidence so much that SpaceX begins to take an interest.

Instead, SpaceX intends to fund their RLV development by selling launch services on the expendable configuration of the Falcon 9. This is good in a number of ways, most notably that it gets into the orbital launch business early, establishing a record of success (hopefully), and has given SpaceX the rocket engine and other components necessary to even start thinking about making a reusable vehicle.

The alternative to both of these paths is to simply have enough up-front funding to buy rocket engines and components from existing providers. For example, the RL-10 from Pratt & Whitney Rocketdyne is considered one of the most reliable rocket engine families available with variants that have been tested rigorously for reuse. Many single-stage to orbit (SSTO) designs of the 1990s just assumed this engine, and the cost, most likely because it was used in the DC-X. SpaceX didn't have this option because their funding was meager by aerospace standards.

The Mars Dream

Elon Musk's plans to send humans to Mars are simply not realistic. Or, at least, that's what I'd say if I had any idea of the details. From all the times I've heard the dream I've managed to garner that basically he's adherent of Bob Zubrin's vision of men braving the perils of space to explore the red planet, with families of immigrants following close behind. This is complete with the heavy lift fetish.

Despite decades of examples that heavy lift can never be cheap, SpaceX has redefined the idea by claiming their upcoming Falcon Heavy launch vehicle will break the $1000/lb barrier and usher in a new age of cheap access to space. The aspirations for even bigger launch vehicles (presumably with even cheaper prices per lb) run deep.

Advocates of staging propellant in orbit, assembling and refueling deep space exploration vehicles which are launched on more modest sized rockets should not be surprised if they find heavy lift advocates counting SpaceX in their camp - but they often are. This defiles the traditional battle lines, with RLV advocates more commonly coming down on the side of propellant depot advocates, if not simply because one of the best uses for an RLV is filling propellant depots with propellants.

As such, it seems that the dream of Mars at SpaceX is essentially Mars Direct with a single heavy lift launch vehicle throwing a Dragon-sized capsule, with stir-crazy explorers, directly to Mars escape velocity. Zubrin has written of such a plan, claiming a Mars landing by 2016 is possible using the Falcon Heavy. It looks good on a cocktail napkin but the same old hand waving is required to shoo away the issues with those pesky human factors like radiation protection and artificial gravity generation.

NASA Assimilation

Practical and profitable space activities are much more effective for exciting public support than dreams of Mars exploration, but it is clear NASA is not going to industrialize space - it threatens the status quo - and today NASA remains SpaceX's greatest customer.

The goal of SpaceX is human spaceflight, and the greatest repository of knowledge about human spaceflight is NASA. As such, it would appear obvious that getting NASA to help you to fly humans safely is a good idea. The way to do that is with Space Act Agreements. This is what SpaceX did under the COTS program, and later under the CCDev program.. and they got paid for the privilege. As a result, the Dragon spacecraft will soon be fully qualified as safe for human habitation on orbit as it will be berthed to the ISS and have astronauts inside it.

The problem is that NASA is a precocious customer. They know what they want, they think they know even better than you do how to make it, and they feel no guilt about changing their mind halfway through the project. As such, Space Act Agreements just totally grind NASA's gears. They don't have enough control.

NASA money is like heroin.. once they start taking it, most people find it very hard to stop. There's a dependence that has grown between NASA and SpaceX, and although it is obviously a love-hate relationship, it's going to be very hard for SpaceX to let go.. but, inevitably, they must. The current needs of NASA are very different to the long term goals of SpaceX.

Promises, Promises, and Delays

SpaceX promises a lot more than they deliver. Over time those promises have changed, with the old promises being forgotten, and new promises being made with more showmanship. Failure is to be expected, with plans changing in response to the lessons learned, but doing so requires clear acknowledgement that there was a failure.

In September this year it was revealed that the second flight of the Falcon 9 had experienced an engine anomaly. While it later became apparent that the issue was minor and not unexpected, the immediate response by the space media was to pounce on what could be a hot story. Quite a number of people I talk to have expressed dismay at the way SpaceX handled the situation, including the lawsuit against Joseph Fragola earlier in the year. While I certainly don't subscribe to the view that SpaceX should be anywhere near as open as NASA with their proprietary information, I do agree that it is indicative of a deeper problem with their engineering culture.

Oh, and we're still waiting for a Falcon 9 flight in 2011.. seems it isn't going to happen.

The Business Case

Now I'd like to talk about the elephant in the room. Fundamentally, SpaceX has a shoddy business case which is best described as a house of cards.. that they're still trying to play poker with.. and there's dogs at the table, and they're smoking cigars! Yeah, metaphor.

The launch business is about volume. If you can get your launch rate up then you can charge less for each launch because the fixed costs will be spread over more launches. SpaceX hasn't done that yet, but they're already charging less than anyone else in the business. This is a common criticism of SpaceX, which most of us in the advocate community love to retort by saying something like: Elon says SpaceX has been profitable every year since 2007!

Okay, that's great. How? There's really only two possible answers: NASA's money, or booking fees. If it is just the former then SpaceX is destined to become just another NASA lackey. So we prefer to think it is the latter - but that means they're living on their seed corn. Eventually they're going to have to actually fly these payloads or give back the deposits. So the acid test will come when SpaceX is called upon to launch and turn a profit in the same year. At that time we will discover if SpaceX is getting the launch rate they require to amortize the fixed costs such that their revenues exceed their expenses. Only then will we know if their prices were realistic.

Suppose they're not. What options does SpaceX have then? Obviously, they can't rise their prices much - that will put them in the same market as the existing providers which have a much better track record (and much better ties to the biggest customers in the government). SpaceX is competing on price, so they will have no choice but to reduce their expenses or increase their flight rate. Reuse is their strategy for doing both of these approaches simultaneously.

There's only one problem: the inherent assumption that there is a market for cheap lift, and that this market can come online fast enough to provide the demand to both amortize their fixed costs and fund their reuse development. In the space community we have a name for this kind of faith: if you build it they will come [no really, watch it!].

If you ask Elon Musk why he is building something which is totally illogical, he will give you the story about the Mars dream. While I don't fully subscribe to the space-based solar power vision, preferring the human tended maintenance of geostationary orbital satellites variety of industrializing space, at least they have some practical idea of what might be economically valuable activities to do in space.

SpaceX is, unquestionably, a bold faced shot in the dark. It is going all-in on the boat hoping that the river will give you a straight flush. It's ballsy madness, and that's why we love them.

Why Commercial Crew Is Doomed

2011-10-27T12:06:00.001+10:00

NASA's Commercial Crew Development program, or "CCDev", has been a resounding success - and that's why they're not doing it anymore.

Inspired by the earlier Commercial Orbital Transportation Services program, or "COTS", and funded by the American Recovery and Reinvestment Act of 2009 stimulus to the tune of $50M, CCDev came out swinging in 2010 with five US companies producing impressive results on what was essentially bonus pay to NASA. As such, it was no surprise when a further $270M was provided for the second round, or "CCDev2". This round is now coming to a close, with continuing achievement from US companies with minimal oversight from NASA. Also, a number of "unfunded" CCDev agreements have been made which receive only use of NASA facilities and expertise - they too have been successful.

With all this success, it might seem strange that NASA is dropping the CCDev program - but they are. They intend to move on to a "procurement" process where a number of companies will be required to submit designs, to be reviewed by NASA, with an eventually "down select" to one or possibly two approved providers for the next phase. The Commercial Crew Program, or "CCP", requested funding for the next five years is $850M/year or $4250M total, but at this time it appears unlikely that they will get more than $500M in the first year.

No, that's not a misprint. Here's a graph to hammer home the point.

Why the massive jump? The simple answer is given by acting program director Phil McAlister's comments at the 2011 International Symposium for Personal and Commercial Spaceflight - the commercial crew office has grown to 250 people, many of which are spending their days writing requirements and regulations and have been for "the last two years". In the near future, a number of these staff will be "embedded" into the companies doing their initial design work. This massive increase in oversight comes with a switch from Space Act Agreements - where NASA pays the partner only after agreed upon milestones have been met - to Federal Acquisition Regulation contracts. Although it is increasingly obvious that "partners" are becoming contractors, and NASA is taking control over the industry, McAlister continues to downplay the change, stating that it is "just rhetoric from people who don't want to engage in debate".

Well here's some debate. Fundamentally, the COTS and CCDev rounds were about partnership. NASA was not in control and this was a good thing - for the industry, for NASA and for the taxpayer. Yes, Space Act Agreements have been proven to work, but it's not just about that - it's about who has control in this relationship. Under the COTS/CCDev program, a partner could say no. They could say they weren't interested in pursuing a proposed milestone and NASA had to negotiate. The pay-on-performance standard encouraged partners to only take on milestones they knew they could achieve and, with good faith, NASA had clearly defined. Those milestones represented where the goals of the partner matched the goals of NASA - which many don't seem to understand are necessarily different.

During a congressional testimony today, where Elon Musk was a witness for the first time (see this summary in PopMech), Congressman George Miller (D) asked two questions which insisted that eventually NASA will have just the one provider for commercial crew. Later, Congresswoman Donna Edwards (D) expressed concern that NASA is creating a US monopoly on commercial crew. Setting aside that these people are supposed to be telling NASA what to do, not meekly asking for a forecast of the future, the NASA representative - William Gerstenmaier - essentially agreed with the assessment, stating a lack of funding to support two providers.

Oh, did I not mention that? Yes, NASA thinks nearly five billion dollars isn't sufficient to get commercial crew providers to a point where they can start actually paying them for seats. How much exactly they're going to pay them for seats is anyone's guess. SpaceX will happily tell you that they can do $20M/seat, but that assumes 28 seats per year. Which could mean anything because NASA can't actually tell you how many seats they want. NASA at least wants the price of seats on US commercial crew providers to be below the price of seats on Soyuz, but they seem to have no clue anymore why that is. As such, this has encouraged a number of hilarious Congress-does-math moments where the representative will add together the cost of development, price per seat by estimated number of seats, get a number which is bigger than just continuing to buy seats from the Russians and wonder how this is going to save NASA money. Hint: it's not. That's not the goal. The goal is to kickstart the industry by having NASA as an anchor tenant. The only reason to care about the Soyuz price at all is to ensure the US commercial crew providers are competitive in the international market. This should be obvious but NASA/Congress are stocked with morons.

Here's a prediction.. you heard it here first.. that whole lower-than-Soyuz-price thing will go away real soon. I think this will not be the last way NASA breaks the former-partners making them uncompetitive. Ultimately, the product that NASA wants - the mythical space transportation system that will keep the precious astronauts safe on their purposeless jaunts to "occupy" the ISS, maintaining international relations and supervising ants sorting tiny screws in space - is incompatible with actual productive use of human spaceflight. When the commercial markets fail to materialize, the government can say "we told you so!" and essentially nationalize the industry, as they did with launch vehicles.

Briefly, how was it ever supposed to work? The vision, for those who can remember it, was for NASA to simply buy tickets on commercial crew transportation providers. It was supposed that a promise to buy some number of seats per year would have been enough to encourage private development of the vehicles. This of course was naive, as a promise from NASA is about as bankable as a promise from Congress - that is, worthless. So instead, some money was thrown over the wall with a minimum amount of whatcha-gunna-use-it-for? The hope being that private investment would come to the table. This worked! So the sensible next step is to keep doing the thing that works.

Part II: The Market

What would happen if NASA continued to encourage the industry to develop, instead of embarking on a premature "procurement" process for their own piddling little needs? The answer is glorious: multiple commercial crew transportation providers racing to be the first available to offer seats. Actual price competition and ongoing innovation. This would open new markets and the virtuous cycle would open up the entire frontier.

But... so many people can't remember this vision - if they ever knew it at all. We regularly hear the proud proclamation that the government is the only "market" for human spaceflight. Ok, maybe they're willing to grant that there's a market for a few "overly rich tourists", yes, they really use that word, and maybe there's some other countries that would like to have a space program but don't have the wherewithal to slap together their own big-rocket-and-capsule program, but that's just icing on the cake. Even the commercial crew transportation providers seem to be ignorant of the actual market which is out there waiting to be tapped. Even Elon Musk seems to be ignorant of the real market.. there, I said it. Talk of colonizing Mars someday is great, but that's not where the money is right now.

I can hear the space solar power people screaming from the balcony. They know the answer! And while I appreciate their enthusiasm, I think they're wrong. Someday, space solar power will be operational and human spaceflight to maintain those massive solar arrays will be necessary, but that day is not here. We should keep them firmly in mind and think about their needs when making decisions about on-orbit capabilities, but right now they're still on the ground.

No, the market I'm talking about is the one space market that has consistently made profits since the beginning of the space age. In 2005 PanAmSat launched the Galaxy 15 telecommunications satellite, its ownership was later transferred to Intelsat. In April of 2010 control was lost and the satellite starting drifting, causing significant hazard to other satellites. More importantly, the satellite was out of commission and losing money every day. An estimate of the loss of the satellite, was required for accounting purposes and a figure of around $4194M was given, or ~$400M per year for the expected remaining lifespan.

This gives us some idea of the acceptable price for a satellite "rescue" mission out to geostationary Earth orbit. It's hard to imagine NASA screwing up commercial crew so much that such a mission could be made unaffordable by US suppliers, but if seats are available on the Russian Soyuz - as they will be when NASA finally switches to commercial crew - the inability of US human spaceflight providers to beat the Soyuz price will suddenly become important.

Much more interesting, I think, is to consider the current SpaceX pricetag of a Falcon 9 / crew Dragon flight, upgraded to the Falcon Heavy, and before any of the price reductions promised by reusability.. let's say, $200M. At this price it is not inconceivable to imagine sending a crew out annually to service a number of satellites in a constellation. When we consider that routine maintenance has never been done on communication satellites, it becomes obvious that extended lifetimes can be achieved that would more than offset the cost.

In short, NASA isn't the market for human spaceflight, it isn't even the icing, it's the free frogurt - don't eat it.

This Is Why Space Settlement Is Important

2011-09-22T21:49:00.002+10:00

It's the end of civilization.. or so some would have us believe. If they don't get their wish, they intend to take it.. by force. Humanity going into space isn't about leaving them behind, but wouldn't it be nice?

With my most humble apologies to Jeff Greason.

As a follow up I posted this over at kuro5hin.

Cancelled Crew Transportation Systems

2011-09-20T08:01:00.003+10:00

EML1 Buildup

2011-08-30T15:10:00.000+10:00

Today's space launch market is used to place satellites - commercial, scientific and military - into orbit, with the majority going to the geostationary orbit. In all such cases, the launch vehicle does not perform the final maneuver to circularize the orbit. The satellite is dropped off and circularizes its own orbit using on-board propellant. This is a significant delta-v change of about 1.6 km/s, and the remaining fuel is used to maintain the orbit, usually for 25 years or more.

Launch to Geostationary Transfer Orbit, circularize using on-board propellant. This is the standard model for how satellites are deployed into space. It is a mature process which has served us well for decades. However, when planning an exploration architecture, it has always been treated as irrelevant.

Here is a list of some current (and one near future) launch vehicles, their listed throw mass to GTO and the calculated mass that can be placed into the first Earth-Moon Lagrange point using a 312 second specific impulse storable propellant thruster (GTO to EML1 delta-v is 1.27 km/s).

Launch vehicle	Mass to GTO	Mass to EML1
Falcon 9	4680 kg	3090 kg
H-IIB 304	8000 kg	5282 kg
Long March 3B/E	5500 kg	3632 kg
Proton	6360 kg	4199 kg
Atlas V 551	8700 kg	5745 kg
Ariane 5ECA	10050 kg	6636 kg
Delta IV-H	12980 kg	8571 kg
Falcon Heavy	19000 kg	12546 kg

What should be obvious is that there is quite a healthy international stable of launch vehicle providers, and they're all geared up for sending payloads to GTO. What is perhaps not obvious is that by going from GTO to EML1 I am seriously cheating myself. I don't mind because throwing to a lunar transfer orbit is something all of these vehicles can also do and, in all cases, the subsequent transfer to EML1 will be less than a transfer from GTO. As such, we can accept the numbers above as accurate, even if they are overly conservative.

So what does this mean? Suppose we want to land a payload on the surface of the Moon. One option is to simply pick the biggest one of these rockets and fly it directly to lunar orbit and start our descent. The total delta-v for such a mission is likely to be about 3.2 km/s, which means we can land a maximum of 6676 kg.

Suppose, instead, we fly to EML1 and pick up fuel. The table above indicates we can put a maximum of 12546 kg to EML1, and the delta-v from EML1 to the lunar surface is 2.52 km/s, so we need 16043 kg of fuel to make the trip. Because we're using storable propellants, this can be delivered over a long time using whichever provider offers the best price, or over a short time by engaging as many providers as become available.

Although this is just a rough analysis, it shows that we can land twice as big payloads by building up EML1 with propellant, without the need for any new launch vehicles, new technologies or even new ways of doing business, and we could start doing it right now.

Dreaming About NASA Mismanagement

2011-08-13T10:16:00.000+10:00

There's so many things packed up in this clip. For a start, the House isn't trying to cut the James Web Space Telescope (JWST) because "we don't have the money" or to save money or for any budgetary reason what-so-ever. The House is trying to cut JWST because the Government Accountability Office reported that NASA, and the contractor, have been mismanaging this program. They reported this three different times and required reports on what NASA was going to do about it - NASA didn't provide those reports. The House even said that the reason they were looking to cut JWST was to send a message that ignoring oversight will not be tolerated.

Does that mean the JWST isn't important? No.. no-one is saying that. Everyone agrees that JWST is important and that it will give results of significant scientific discoveries should it ever be completed and launched.. but when will that be? Within a two week period - after the House suggested cutting the budget - the program managers said 2020 or 2018 - neither answer was given in writing. Both answers were contingent upon an increase in their budget.. there's a word we use for declining to increase the budget of mismanaged projects: smart.

So is that the end of JWST? In the minds of NASA-can-do-no-wrong advocates, yes. They immediately declare that you're just not throwing enough money at the problem. It goes something like this: Oh, Hubble was massively overbudget and even broken when it launched. If we hadn't thrown more money at the problem we wouldn't even know about [insert discovery of cosmic significance here].

Meanwhile, the cosmologists are going around saying that the JWST is "essentially complete" or that "we've already built it". This isn't just the sulk cost fallacy, they actually think the JWST is ready and Congress is pulling the rug out from under them. This isn't the case at all, and not even NASA is making this claim. I've been suggesting that, if this were true, people who really want to see JWST fly should be calling for a firm fixed price contract - where the contractor covers the cost overruns, and NASA has less opportunity to screw things up - which has been proven time and time again to result in projects that are completed on-time and under budget.

Failing to mention any of this, Tyson then goes off into one of his standard rants. Oh, we've stopped dreaming. We don't look up. We've turned inwards. Can you imagine why? Hint: it has something to do with NASA mismanagement.

Back in the 1960s people dreamed of going to the Moon. Guess what? NASA went to the Moon. Was NASA not grossly mismanaged back then too? Of course they were, but they were given the mandate to "waste anything but time" and that is one thing government does well: waste.

What did people dream about in the 1970s? Space settlement. These dreams became plans, that wasn't the problem. All the engineering analysis at the time indicated that NASA could do it, so what happened? The plans called for cheap access to space and that requires the opposite of government: efficiency.

Instead, NASA became a government agency focused on "international cooperation", with first the Shuttle-Mir program and later the International Space Station, and while I'm sure there was plenty of people out there dreaming about more cooperation between nations, it had little to do with looking up.

We've Already Got Propellant Depots

2011-08-06T15:07:00.000+10:00

The solution to so many space logistics problems is: use a bigger rocket. Propellant depots allow you to add another solution: use more rockets.

Now, for some reason, many people who are advocates of propellant depots object to just using existing space storable propellants because that would mean you'd need to launch more mass than if you used cryogenic propellants. Well, so what? More launches - that's a good thing!

We don't need technology development to make propellant depots work. They already work.. we already have one in orbit!

Suppose you want to send 100 tons to Mars transfer orbit. You need either 236 tons of storable propellant or 144 tons of cryogenic propellant (and that's being overly generous to cryogenics). Instead of 5 Falcon Heavy launches you now only need 3. So what? How much is that worth?

So, ya know, NASA has selected companies to study storing cryogenic propellants in space.. and that's great. Technology development, in general, is fantastic and it makes things better in the future. Unfortunately I'm already hearing people say "woohoo! Now we'll have propellant depots and we won't have to waste $38 billion on a heavy lift vehicle to no-where!". Well, no. We already have propellant depots and we already don't need heavy lift to go beyond LEO.

There is, however, a few things that we are in desperate need of.... the political will to go, anywhere, on the government side, and an outspoken willingness to go it alone, if necessary, on the commercial side.

All we need is a really long tether!

2011-08-05T14:09:00.001+10:00

I've written previously about non-rotating artificial gravity in Earth orbit. After recently watching this stinker I broke out the code I use to figure out gravity gradient effects. Surprisingly, this seems pretty good:

	Altitude	Mass	Gravity
LEO Station	300 km	273 tons	0.999 g
GEO Station	35786 km	30 tons	0.38 g

Of course, this is a much longer tether than in the film.. but hey, Danny Baldwin is in it - he doesn't make good movies. Anyway, the high station could be an ISS-style module with airlock and docking ports for satellite servicing vehicles. The low station would be a true permanently inhabited facility where people can live for years at a time without fear of bone mass deterioration or the other negative effects of zero gravity. To maximize space we may be tempted to use inflatable Bigelow modules, but we have to consider how they will behave in full gravity.

The only sticking point left is radiation. On the LEO station crews have much less exposure to cosmic radiation thanks to the Earth's magnetic field, however they receive just as much from flying through the South Atlantic Anomaly. As a result, radiation on the GEO station would be 2.19 times as high during solar maximum and 6.568 times as high during solar minimum. If that seems confusing, just remember that the Sun's magnetic field provides most of our protection against cosmic radiation, and it does that more at maximum than at minimum.

One solution may be minimagnetospheres but, again, technology developed for zero-g rarely works unmodified in full gravity. The best solution may simply be appropriate mass. The requirement that the low station be 9.1 times more massive than the high station means that both will have to grow simultaneously but getting mass from LEO to GEO is pretty easy when you have a tether joining the two altitudes.

You may be asking: how plausible is this? Or even: isn't this just the Space Elevator? I estimate it is at least two orders of magnitude easier to do than a space elevator and would only require (vast amounts of) existing tether materials. The cost is most likely dominated by launch costs that should be around $800M in a few years time.

Annoying Anonymous Comments

2011-07-15T17:14:00.002+10:00

Lately I've attracted a number of annoying comments. As such anonymous comments are henceforth unwelcome. I apologize to everyone who commented anonymously previously without being annoying but Blogger provides me with no other means of sending the jerks packing.

NASA Is Going To Explore Deep Space

2011-06-22T12:15:00.007+10:00

Did you hear? The MPCV is crossing the country. You can go take your children to see the *cough* future of human spaceflight. Thanks to Rand Simberg for all the help with this video.

Fooling Yourself

2011-06-10T09:59:00.001+10:00

I was asked to comment on this article. I think Greg’s replies have done a better job than I ever could have in proving the futility of such comments.

According to him, the world consists of the established and successful NASA and the young and inexperienced "New Space Boys" and no-one else. Inexplicably the Boeing corporation exists in both camps.

The "whisper campaign" against Constellation, which no sensible person would deny existed, is absurdly attributed to "New Space Boys" in an effort to rewrite history – it was clearly NASA civil servants, contractors and other malcontents under the DIRECT banner who led that effort, advocating a Shuttle-derived launch vehicle over Griffin's Ares launch family.

If the civil war inside NASA is to be divided into two camps at all, those are the battle lines which have been firmly established. But like all bipolar characterizations, this is also too simplistic.

The enormity of Greg's worldview is just scapegoating – on the current administration and the new entrants into the much maligned space industry. It's a desperate attempt to understand a complex interaction of multiple players with various goals by pointing fingers and crying foul. This kind of worldview can only be maintained by denial of contradiction, such as the Boeing corporation.

Rebirth Of The Spaceship

2011-05-27T18:27:00.000+10:00

Over the last year the space advocate community has splintered into two major groups in answering the question "where should we go next?" Moon First or Mars First. This division was present in the Review of Human Spaceflight (aka Augustine) committee's final report in late 2009, with the surprising conclusion that there isn't the funds for either, suggesting a number of intermediate destinations first - including asteroids. However, as few people consider asteroids to be truly interesting destinations for the human utilization of space (except me!), the debate rages on.

Many Moon First advocates are "Mars Next" advocates while most Mars First advocates are "Moon Again?" detractors. The former claim that Mars exploration will benefit from lunar exploration, particularly in experience and risk reduction, and perhaps the procurement of propellant. The latter claim that lunar exploration is just a distraction and want to avoid the risk of being bogged down by another expensive obligation (read: another ISS).

NASA, and the Congress, is hedging their bets.. declining to select a camp and insisting that the so-called flexible path will have "off-ramps" for either lunar or Mars exploration.

Perhaps as a result of the deferment, an old camp has resurfaced with a strong central tenant: the true "spaceship". Defined loosely as a vehicle which is assembled in orbit and is never intended to land on a planetary body - although it may do aerobraking maneuvers in a planetary atmosphere. Spaceship advocates talk about lander vehicles rarely and, although the Moon is recognized as a nice buoy to fly around in a shakedown cruise, the intended destination is clearly Mars.

For many years, this camp has been silenced by a powerful force: The Mars Society and its charismatic leader. With a desire to cut out all distractions, Bob Zubrin has rallied against "Battlestar Galactica scale plans" for getting to Mars, advocating trips of endurance of small crews in tightly packed modules - small enough to fit on the top of a single heavy lift launch vehicle and launched directly from the surface of the Earth to the surface of Mars. What happened?

It seems that the last 20 years of advocating for the simple, elegant, and dangerous Mars Direct plan has been easily swept aside with just a single picture:

This sharp looking spaceship, with its command deck off to the side like the Millennium Falcon, and its inflatable artificial gravity ring promising Bigelow budget sweetness, has inflamed a deep longing for the sci-fi universe we were all promised - humans exploring space for years at a time with large crews.

The problem is propulsion. The tiny Firefly-like cluster on the rear of the ship is woefully inadequate for even the most advanced nuclear thermal propulsion system. The solar panel array is football fields too small for a solar-electric propulsion (or SEP) system. A chemical rocket stage to throw this vehicle to Mars and back would be so much bigger than the vehicle that we'd have trouble seeing it without zooming in... or so I've heard. How true is this objection?

The first problem comes when the objector talks about assembling the spaceship in low Earth orbit. This is an understandable assumption given that all on-orbit assembly to-date has been done in LEO, namely the international space station. However, for some time now the Earth-Moon Lagrangian points have been identified as the perfect location for staging for deep-space missions. This is not to say that no on-orbit assembly would be done in LEO, but once completed the resulting module could be ferried by a SEP tug up to L1. Whereas crew transfer vehicles would take the faster, more energetic path.

Often platforms at the Lagrangian points have been called "gateway stations" and for good reason. It takes less than 1 km/s of delta-v to go from L2 to a Mars transfer orbit. Transiting a large structure from L1 to L2 requires about 100 m/s of delta-v if you need to do it fast, but can be done with just 10 m/s or less if you take your time.

The Moon is so close and lunar water is so abundant that can be cracked into cryogenic propellants or used for radiation shielding, drinking, grow crops, etc. A purely chemical propulsion system quickly becomes feasible, but some other techniques such as solar sailing appear to be very interesting to me.

Although that could be because I just saw the latest Johnny Depp pirate movie. Arrgghh.

You've gotta love him

2011-05-18T16:07:00.003+10:00

For anyone who wonders why I still love Bob Zubrin, watch this video:

It's the passion.

For anyone who needs a horrific demonstration of closed world thinking, combined with a little intellectual elitism, read on.

Please Stop Lying To Children

2011-05-07T20:03:00.002+10:00

Here in Australia we have a shameless tradition of claiming celebrities who are not quite Australian. The best example of this is probably Mel Gibson - back when anyone wanted to claim him - who wasn't actually born in Australia, he just lived here for a portion of his childhood. It is generally agreed that anyone who was born in New Zealand can never be considered an Australian (just kidding kiwis, we love you) but if they're famous they're automatically Australian. The common joke is that any celebrity who so much as flies over Australia will be offered citizenship.

Something like the Australian celebrity phenomena happens when people start talking about NASA spinoffs, here's how it works: a speaker creates the implication that civil servant NASA scientists developed some new technology which was subsequently "spun off" to form a commercial product. The most common example of this is Velcro, but there are plenty of others. Whenever you dig into these claims you almost always discover that the entirety of NASA's contribution was in the form of a check. Some people don't even see the deceit in this, suggesting that any NASA funded research is NASA research and therefore any commercial products that result are spinoffs. I've always wondered how the scientists and engineers who do the work to create these products feel about that.

It is an obvious truism that no human-made object could have been placed into space had it not been for the space program of one nation or another. Oh wait, no, that's not a truism at all is it? The first rocket to leave the Earth's atmosphere was a German V2 rocket in 1944, long before anyone had a "space program". Despite this, it seems a lot of well meaning people want to perpetuate the myth that everything in space is a result of the space program.. and a lot of things on Earth too. Watch this short video for my least favorite demonstration:

It disappoints when a speaker says something like this.. it fills you with inspiration for about five seconds, only to have the nagging rational part of your brain chime in with: umm, excuse me? That's not actually true, ya know. I think kids who are inspired by such speakers to follow their dreams will feel terrible betrayal when they eventually discover they've been lied to.

Before anyone accuses me of Tyson bashing, let me say that I'm otherwise a fan of his work and encourage everyone to watch the full 2.5 hour talk. Maybe he doesn't know that NASA didn't invent cordless power drills and their contribution to LASIK eye surgery amounted to writing a check long after it was invented, and maybe he's unaware of the history of the global positioning system and that "space exploration" had nothing to do with it. I don't know, but considering how awesome he is, I find that extremely hard to believe.

But let's take this argument where no-one seems to be willing to go.

We all love the global positioning system - you might say it is the pinnacle of human achievement - surely we should support any program of government spending that can result in fantastic technological marvels becoming such an everyday part of our lives, right? If you don't necessarily agree with that, then perhaps it is because you know the primary justification for building and launching the GPS satellite constellation was global thermonuclear war.

In fact, the development of satellites in general and giant space telescopes in particular, was the cold war need to spy on the Soviet Union. Love the Hubble space telescope? Well then, you should support more government spending on the military industrial complex. Actually, you should long for the days when school children practiced hiding under their desks with visions of nuclear annihilation dancing in their heads. With the Soviet Union gone we'll have to find another enemy but that shouldn't be too hard.

Or - just maybe - you might think that regardless of the spinoffs and the side benefits, it was still bad to have forty years where two great superpowers teetered on the edge of oblivion staring at each other across the void and hoping neither would be so stupid as to make the first move in a game neither side could win.

Similarly, the space program cannot be justified by spinoffs and side benefits. It can't be justified by how many kids are inspired to become scientists and engineers instead of lawyers and doctors - no wait, politicians, yeah that's better. In order to convince your fellow taxpayers that human spaceflight is in the national interest you have to say what it is for and why that is a good thing. We can disagree on what that is, but the last thing we should do is give up and list the side benefits as the actual purpose.. and stop lying to the kids ;)

The Role Of The Goverment

2011-04-30T12:41:00.000+10:00

Recently I've been pondering the purpose of government spending on human spaceflight. My own politics typically preempt me from such thoughts as I honestly do believe that taxes should not be collected to fund non-essential services. However, I pride myself on being able to set aside my own ideology and think like others, in the hope of learning more about their motivations and possibly even understanding their actions.

With that disclaimer out of the way, what is the legitimate role of government in human spaceflight?

In general, the government should not compete with private industry. For example, if there is domestic production of cars, it is wrong for the government to set up their own car shops. Whatever goal the government is trying to achieve by doing such can almost certainly be better served through regulation or incentives. It's wrong because of the effect it would have on the industry. With the power of the treasury behind it, the government can sell cheaper or invest more in research to make a more attractive product, and while it's true that this would appear to be a public good at first, the resulting elimination in choice as the commercial providers go out of business will inevitably lead to stagnated innovation. Without the profit incentive, all providers fail to respond to consumer demands.

As such, the government should make the fullest use of existing private industry, and encourage the development of more industry that is in the public interest. For example, when launching payloads to orbit, it would be wrong for the government to build their own rocket - or contract someone else to build one for them - if there are already rockets on the market that can serve the purpose. Furthermore, the government should plan their payloads around the capacity that is available and offer incentives for industry to improve their capabilities in the future.

In order to avoid crony capitalism, the government should use competitive bidding and punish price collusion. The government should encourage providers to create products that have customers other than the government and not place unique demands on providers - or at least, such demands should be temporary. When it is in the public interest, the government should allow providers to fail and encourage the healthy functioning of the market.

Ultimately then, what is left for government to do but hand out money to private industry and ensure it is competitive and healthy? Assuming you believe the government should be spending tax dollars, is this just "stimulus" we're talking about?

I think a lot of people see a greater role for government funded human spaceflight than just stimulus. If you agree that government should be involved whenever something is in the public interest but not in the, often short sighted, commercial interest then stimulus is probably enough, but even I see a greater role for government than this.

I often hear claims that human spaceflight is about "research" or "science" that private industry is unable (or unwilling) to do because the return on investment is not immediately apparent. To me, these claims always ring hollow as so much space research is or could be done without humans. Of course, everything I've said thus far could also be applied to robotic spaceflight but it often is already. The situation with human spaceflight seems to be somewhat different.

To me, the goal of human spaceflight has always been obvious. This may surprise some people as I regularly solicit answers to "the why question" and I never seem terribly inspired by the answers I get. The purpose of human spaceflight is to open a new frontier. I have become aware that many people don't know what this means so I will put it more crudely: the purpose of human spaceflight is to find more lands to conquer so that we don't end up weeping like Alexander the Great.

Rather than being uninspiring, some people find this answer outright distasteful. I believe this is because they think of conquering people. So far as we know, the only people in space are the six expedition crew members of the ISS, and no-one is talking about conquering them. I submit that the very first lands which humans occupied, which never before had been occupied, were conquered. I don't know why we can talk about "conquering challenges" but we can't talk about conquering space. It's the same thing, breaking through our limits to increase our sphere of influence.

Space is an especially harsh environment to conquer. It is a grand challenge as JFK described it, but I disagree that this is a reason to do it. To me, that was just a cold war way to say stimulus. The public good created by human spaceflight is the opening of a new frontier. It is a gift of opportunity that we give to the next generation.

Final thought: there are other organizations that reject the commercial interest to act in the public interest. And then we have people like Elon Musk, Bob Bigelow, Jeff Bezos and others, who act both in the commercial interest and in the greater public interest. The frontier doesn't have to be opened by a government space program but, if you've got one, at least give it the right goal.

Page 113

2011-04-17T20:46:00.002+10:00

I'm currently reading "Choice Not Fate" by James A. Vedda, Ph.D. It's a dry volume of 201 pages that rambles from historic interpretation to beltway praise for inane space policy and regularly promises the reader discussion on side points in later chapters that never come. On page 113 the author finally gets around to saying what I believe the entire book is actually about.

In the future, NASA must be prepared to make judgments that will be interpreted as endorsements of particular companies or technical paths serving space markets, such as who receives government assistance and who doesn't. This places NASA in the position of making industrial policy decisions on who gets to develop space infrastructure and resources.

Jesus, really? Up until this point I took the author's constant negative references to partisanship as a distaste to politics and assumed he had no particular leaning, way to yank the veil back dude. Now I have to consider whether not I should finish reading this pinko trash.

Update: Well, I made it to page 139 and after telling us why eliminating aging and the invention of teleporters might have unexpected side-effects (gee, ya think?) Dr Vedda introduces the reader to the travesty of ITAR restrictions as they related to the space industry. He explains that these laws were extended from just guns and bombs to anything that may have a "duel-use" (sic). Ok, so it's just a typo right? If it is, it's one he makes multiple times. I guess the state department is afraid of a return to "satellites at 100 paces" :)

Update: I finished it. Overall I agree with the message of this book: the industrialization of space has and will continue to improve the lives of people on Earth. So if you know someone who has the same political leaning as the author, I'd recommend this book to them.

They All Laughed At Christopher Columbus

2011-04-05T12:14:00.001+10:00

"I didn't expect to be ridiculed,
for trying our best to change the world."
- Gary Hudson

My review of this book has been picked up by
Moonandback, you can read it over there.

We Need Technology Development

2011-03-12T17:15:00.003+10:00

It seems pretty obvious that we don't currently have the technology to become a spacefaring civilization. Certainly there is stuff in space we could be doing using existing technology, and with great expense, but to really begin the human utilization and colonization of space we need a large variety of technological innovations.

Jon Goff gave a great list of short term technologies that need to be developed before we can really consider society to be spacefaring.

This should be the start of the story.

Charlie Bolden, Worst NASA Administrator Ever?

2011-03-09T15:26:00.000+10:00

Gah! He's telling you the answer and you still can't answer the question.

How COTS-D Was Killed

2011-02-17T12:28:00.001+10:00

Lest we forget, under Mike Griffin NASA awarded to SpaceX an option in their Commercial Orbital Transportation Services contract to develop a crew transport capability. The Space Act Agreement looked like this:

Milestone	Payment
Project Management Plan Review and Crew Demo 1 System Requirements Review	$27,420,000
Financing D1	$10,000,000
Crew Demo 1 System Preliminary Design Review	$22,420,000
Crew Demo 2 System Requirements Review	$25,420,000
Crew Demo 1 Critical Design Review	$20,420,000
Crew Demo 2 System Preliminary Design Review	$20,420,000
Crew Demo 1 Demonstration Readiness Review	$20,420,000
Crew Demo 3 System Requirements Review	$25,420,000
Financing 2D	$10,000,000
Crew Demo 2 Critical Design Review	$18,420,000
Crew Demo 3 System Preliminary Design Review	$20,420,000
Crew Demo 1 Mission	$15,420,000
Crew Demo 2 Demonstration Readiness Review	$18,420,000
Crew Demo 3 Critical Design Review	$18,420,000
Crew Demo 2 Mission	$8,420,000
Crew Demo 3 Demonstration Readiness Review	$18,420,000
Crew Demo 3 Mission	$8,420,000
Total	$308,300,000

As with all the COTS milestones, SpaceX would not have received these payments until the milestone was completed. The finance milestones were required to demonstrate that SpaceX could fund and complete all the milestones without using the payments from NASA as "seed money".

The COTS-D option was never activated. You may even hear some people at NASA say that it was never "funded", this is wrong. The final nail in the coffin of COTS-D came in the form of an intriguing exchange between Sen. Bill Nelson and then acting NASA Administrator Chris Scolese. Here's the relevant part of the long transcript.

Senator Nelson. In last year's authorization bill, there was guidance to NASA about COTS-D Space Act agreements to develop a U.S. commercial alternative to Soyuz. We authorized $150 million in funding for COTS-D. I noticed that you are
putting $150 million of stimulus funds toward the Commercial Crew and Cargo program, but not actually initiating COTS-D agreements. Why are you not initiating these Space Act agreements?

Mr. Scolese. Well, we are working the commercial program as you defined. There was cargo on it. We have those two contracts with SpaceX and Orbital to do cargo. We had one for COTS-D. I cannot recall a specific--$150 million to go on to COTS-D. We did this year in the stimulus identify $150 million to stimulate a commercial activity, and it is broken into two pieces: $70 million to go off and develop capabilities that any visiting vehicle would need, including commercial vehicles, and that includes developing the human space flight rating requirements, the requirements that you need to be certified for human space flight. As you well know, we build human spacecraft and design them so infrequently that we have to write those requirements down. So part of this is to make those available to everybody, make them understandable to everybody, and that will help not only the commercial providers broadly, but all of us. And then $80 million to stimulate activity for a commercial crew.

[recess for a vote]

Senator Nelson. I want to go back to the question that I had asked you earlier. You described the breakdown of how you intend to program $150 million for Commercial Crew and Cargo. Instead of putting the dollars into the various component pieces that would enable crew capability, would it not make more sense just to invest that in a milestone-based demonstration flight?

Mr. Scolese. We discussed that, and we believe that we need to take a measured approach to developing commercial crew. As you know, again it is a very difficult prospect to develop a crewed vehicle to carry crews safely to and from space, let alone rendezvous and dock with the Space Station. So we are working a measured development where we work progressively from developing the capability to get into space, to conduct the rendezvous and docking with the Space Station, to crew rescue, which can be done without having to worry about crew escape,
all the way up to carrying crew. That is the philosophy that we are working to achieve. To do that, we needed to do some things that broadly help the community that wants to do this, as I mentioned earlier, about developing clear and concise specs and standards so that we can safely put our crew on those vehicles. And further, I think you have seen the annual report of the Aerospace Safety Advisory Panel that had some questions about the detail of our human rating requirements. So that is all part of what we are trying to accomplish, and we believe that will get us a commercial crew capability quicker and safer than if we were to just go off and suggest that we fund a capability.

Senator Nelson. But that was not what the legislation said. The legislation said that $150 million was funding for COTS-D. In this case, you would not even have to pay until the COTS-D partner was able to successfully demonstrate that capability. Is that not right?

Mr. Scolese. It would be dependent upon how we structured it. Of course, we wanted to maximize competition for the vehicle. As you know, there is only one COTS-D provider.

Senator Nelson. Well, when I say "you," I am referring to NASA, and you were not the Acting Administrator at the time. This is an example of where NASA has not followed the legislation. Now, let me ask you this. Would $150 million be enough to demonstrate that capability?

Mr. Scolese. We would have to look at it, but I do not think so, sir.

Senator Nelson. Well, what do you think it would be?

Mr. Scolese. I would have to get back to you on that, but it would be several times that, I would expect, because recall, we have to develop not only the crew portion of it. We have to develop the life support systems, the launch escape systems, the recovery systems. All of those have to be developed and demonstrated, and $150 million does not seem enough to do that.

Senator Nelson. We had a unique opportunity, if NASA had listened and followed the law, we had a unique opportunity this year between the 2009 operating plan and the additional funds provided by the stimulus bill and the development of the 2010 budget to craft a COTS-D plan that would have funded the program at the level that the folks needed. That path was not pursued. NASA did not obey the law. Again, I am not saying it to you because you are the Acting Administrator since January 20, but I want to point this out that sometimes NASA does not want itself to be helped. We have got to get our act together.

And that was the last opportunity for COTS-D. Had NASA obeyed the law and provided the $150M that was allocated in the FY09 budget, SpaceX could have started COTS-D and completed the first seven milestones. When the $150M in stimulus money came in SpaceX would have been on much better footing to claim part of it. Instead, Sen Shelby was able to divert $100M to the development of Ares I, a vehicle that was later scheduled to be cancelled prompting him to insert language into law prohibiting NASA from doing that. Of the remaining $50M, SpaceX received none.

The official position of NASA seems to be that the CCDev program has replaced COTS-D. SpaceX has put in a bid for the new round, which NASA has been prohibited from starting due to the failure of Congress to pass a budget for FY11. Should SpaceX be successful, they intend to start work on the launch abort system which will also allow the Dragon spacecraft to land vertically on land. While I have been assured that the CCDev program will be "milestone based" like COTS, I still have my doubts that it will capture the simplicity of the COTS-D option.

New Space Music Video

2011-02-14T10:31:00.000+10:00

An idea that has been bouncing around in my head for a few years..

Great to finally get it out.

Making Fusion Rockets Relevant

2011-02-03T13:16:00.006+10:00

If you read the literature on fusion rockets you probably have a pretty firm idea in mind of what they're good for and when they'll be relevant - in "the future". No good fusion rocket paper is complete without a superconducting magnet here, and a magnetic nozzle there - in fact, these widgets are a primary ingredient of any fusion propulsion design and the more infeasible or untested they are, the better. This seems obvious: fusion rockets are the future because we don't have fusion yet.. right? Actually, no.

Producing nuclear fusion isn't all that hard. Amateurs regularly cobble together desktop fusion devices like the Farnsworth Fusor and other contraptions. The significant hard problem of fusion is getting more energy out of the device than you put into it. The current government backed effort to achieve this is the ITER project who are building a tokamak style device, but many other schemes are also being tried, with significantly less funding.

One of these is the dense plasma focus of hydrogen/boron fuel, a combination called focus fusion. The technique is relatively easy to understand. You take a metal chamber and put a single tubular electrode in the middle, ringed by a number of solid electrodes. Pump all the air out with a vacuum pump and then add the fuel until it is at a few torr. Dumping about two mega-amps of current into electrodes causes a plasma compression called the "pinch" in which nuclear fusion occurs. The result is a stream of electrons in one direction, a stream of ions in the other direction and a whole lot of x-rays, and virtually no neutrons. These happen to be the perfect products for producing electricity and if that's your goal, it means you can do it very efficiently.

The challenge of focus fusion is getting enough power into the device to burn the fuel - typically done with a big heavy bank of capacitors - and containing that heat in the plasma for long enough. Hydrogen / Boron 11 (or pB11 as it is often called) is the hardest fuel to get fusion going, requiring temperatures over 123 keV. As such, dense plasma focus fusion researchers tend to use deuterium instead, which only requires temperatures of 15 keV. The government program uses deuterium/tritium which only requires 13.6 keV, but tritium is a little hard to come by - it has to be made in nuclear reactors - and is strictly controlled. Deuterium can be picked up in rented bottles from your local gas supplier.

Using a dense plasma focus device to produce deuterium-deuterium fusion is pretty simple and requires minimal startup costs - especially if you do your homework and learn from the mistakes of others. Unlike pB11 fuel, D-D fusion produces neutrons. Shielding fusion researchers from neutron exposure is easily achieved with two things: distance and concrete. Measuring neutron output can be as low tech as looking for bubbles in a contained gel, and as high tech as CCD detection of scintillator stimulation. When you're producing neutrons you know you're achieving fusion.

Getting back to rockets, let's look back up at how I finished my first paragraph describing focus fusion: producing electricity [..] if that's your goal. While nuclear-electric propulsion sure is sexy, what if our goal is just to make a good old nuclear thermal rocket? Back in the 60s the US did a lot of great nuclear-thermal rocket work. They were using highly enriched uranium folded into a solid core with liquid hydrogen running through it. They got specific impulse in the 850 s (vac) range and had plans to achieve higher power before being defunded for obvious political reasons. So what might a nuclear fusion thermal rocket look like?

As our goal is to produce heat, not electricity, it makes more sense to use deuterium as our fuel. We only need to produce pulses of electricity to feed into the electrodes to produce fusion, and the most readily available technology to do that with sufficient power density is a compulsator. Much like an alternator, a compulsator is an electromechanical device that converts mechanical rotation to electrical energy in the form of alternating current. A high power rectifying bridge converts that to direct current to feed into the dense plasma focus. Compulsators have been built for railguns which produce more than enough current (and way more than enough voltage). I haven't read much on reducing pulse width (sometimes called "rise rate") of compulsators, but the ~2 microsecond pulses needed for dense plasma focus does seem challenging.

The rest of the rocket cycle is pretty standard. The expansion nozzle is cooled by cycling the fuel through it, this heats the fuel enough for a state change to occur and the expansion is used to turn a turbine which pumps the fuel, and finally the fuel is used to cool the core. The only difference is that the turbine serves double duty by turning the compulsator. A smart engineer will recognize that the rotors of the compulsator could be the turbine. Similarly, although all three components are shown schematically as being on the same drive, there most likely will be gearing involved to keep the pump constant.

Unlike a device for the production of electricity, the dense plasma focus will probably be made from copper. This will absorb the x-rays and transfer the heat to the "fuel" (aka, the coolant, traditionally the propellant-which-isn't-an-oxidizer of a rocket has been called the fuel). The already slow neutrons will pass right through the copper core and be slowed more by the fuel, hopefully enough that they don't hit the outer chamber with enough velocity to make it irradiated or contribute to wear.

Speaking of fuel, most readers familiar with nuclear thermal rockets have probably been thinking about hydrogen this whole time. Although compulsators are certainly more mass efficient than equivalent capacitors and the means to recharge them, they are not known for being light. As a fusion rocket is incapable of spreading radioactive material into the atmosphere, the traditional safety concerns of launching nuclear thermal rockets from the ground does not apply. As such, propellant density is once again important and a hydrocarbon first stage fusion rocket doesn't need strap-on boosters trumping its inherent safety.

Space Colonization As The Savior Of Progress

2011-01-26T12:14:00.009+10:00

The idea of Progress, as defined by J. B. Bury, proclaims that "civilization has moved, is moving, and will move in a desirable direction". Ever since the 1960s the belief in Progress has been waning and some would say that it has been completely lost to the current generation. Going beyond Bury's definition, Taylor E. Dark III provides three mutually reinforcing and interlocking premises:

1. NO LIMITS. There are no fundamental limits – nor should there be – on the collective human capacity to grow, no matter how growth is defined (which may be in terms of knowledge, wealth, power, population, or morality). Progress is endless (or at least indefinite for all practical purposes).

2. ALL GOOD THINGS GO TOGETHER. Advancements in science and technology, and the resulting mastery over nature, expand our knowledge, wealth, and power, and, in so doing, bring improvements in the moral, political, and spiritual character of the human race. The elements of progress are linked to one another and mutually reinforcing.

3. INNATE DIRECTIONALITY. There exist developmental tendencies, rooted in societal, psychological, or biological mechanisms, that make it far more likely that human civilization will move "upward," toward greater control and understanding of nature and ourselves, rather than “downward” toward chaos and entropy. Progress is, if not inevitable, always highly probable.

In his excellent paper, Reclaiming The Future: Space Advocacy And The Idea Of Progress, Dark proposes that the space program was insulated from the crisis in the idea of progress in the late 60s and because of this, the new pro-space ideology was just a reaction to social change.

To me, this kinda sounds like fearful Americans, desperate to hold on to their beliefs, turning to the only avenue of society where they can still openly talk about the future with a sense of awe and wonder. This may sound harsh, but at least I'm not suggesting it's all just narcissistic phantasy.

Dark has a different explanation for the desperation: the cancellation of Apollo with no plans to follow on with anything else:

The irony was that they embraced this belief at the very moment that the Apollo program was coming to a close, and the future of NASA and space travel becoming increasingly uncertain. Thus, a strong edge of anxiety and urgency was introduced into the writings of space advocates. The means to ensure progress had been found, but would soon be lost forever if government policy was not properly adjusted. This combination of certainty about the path toward redemption alongside anxiety about the possibility of missing a singular opportunity energized the new pro-space literature, and encouraged the growth of an accompanying space advocacy movement.

With the cancellation of the Space Shuttle (and Constellation), that same sense of anxiety and urgency can be felt in today's pro-space literature.. but perhaps that's just because we're all sick of waiting.

My favorite part of Dark's paper comes in the concluding remarks:

If advances in bio-technology, artificial intelligence, and nano-technology allow humanity to prosper on Earth to a greater extent than ever before, the urgency of the space endeavor is lost. In fact, if one has faith that terrestrial technology will continue to advance, the idea of spending billions of dollars on unprofitable space ventures becomes even less attractive.

Why not just wait until new technologies reduce the cost of space flight to reasonable levels? At that point, normal market mechanisms (such as tourist demand) may allow major increases in human space flight without government intervention. But then, of course, no grandiose ideology of progress will be required, any more than such an ideology was required to people the formerly arid deserts of the American southwest once water and air conditioning became widely available.

Oh the sweet bitter irony. Why wouldn't anyone suggest that maybe there are limits to how far terrestrial technology can advance? Why would one assume that the advancement of terrestrial technology would immediately imply that space-going would become any easier? And what would this "faith that terrestrial technology will continue to advance" be called?

I guess you'd call that Progress.

The Easy Way To The Moon

2011-01-24T22:56:00.004+10:00

I recently described how to fly to the Moon solo using SpaceX hardware. Someone asked me why I worked out an Apollo 8 style flight and didn't just do a simple free return trajectory.. after all, it's a lot easier - and that's actually the reason - it's too dog gone easy. In order to make this interesting I decided to try to think of the easiest way to do a free return trajectory. Preferably, we'd like to use an unmodified spacecraft and launch vehicle and not have to develop any other hardware.

For a start, let's forget this whole idea of an Earth Departure Stage - we'll just throw the Dragon spacecraft to lunar orbit. This sure is simple, but it only gives us 2585 kg to work with. This prompts the question, exactly what is the mass of an unladen Dragon.. yeah, yeah, I know - African or European?

Looking at the Falcon 9 Users Guide we find that it can throw 9358 kg to 51.6º with an altitude of 400 km. SpaceX will happily tell you that the Dragon can carry 3000 kg of pressurized cargo and 3000 kg of unpressurized cargo to the ISS, and has 1290 kg of propellant. So the dry mass has to be around 2068 kg. It's this big number that prompted me to suggest pulling out the heavy docking adapter, etc, but we're not doing that this time.

At some point there is going to be a bunch of used Dragon capsules, and maybe we can get one for cheap. The actual launch is around $56 million, if you can get SpaceX to stop placating NASA's worst fears: another crew lost and everyone asking why the hell they were flying in the first place. If they keep blowing money on a fancy launch abort system, then who knows.. but it'll probably still be smaller than the $150M per seat that Space Adventures is charging for a ride on Russian hardware.

For a single crew member weighing a maximum of 100 kg, you need 11.839 kg of cabin air, 25.83kg oxygen candles, 52.71kg LiHo CO2 scrubbers, and 45kg food and water. Total is 235.379 kg. From our throw mass to lunar transfer orbit we subtract the dry mass and the consumable mass to find 281 kg remaining.

Remember how we took the fuel out of the Dragon? Let's put 245 kg back. This gives us about 300 m/s of delta-v, which is about 10 times as much delta-v as we need to do a free return trajectory. So even if you're flying like Scott Carpenter you should be able to pull it off.

The remaining 36 kg is margin.. or you could take your dog along for the ride.

I have one last thing to say on this insanity. For a while I've been using 3140 m/s as the required delta-v to from Lunar Transfer Orbit directly to the surface of the Moon. Apparently, this estimate is horrible. According to the Lunar Polar Volatiles Explorer concept mission the required delta-v post-TLI breaks down like this:

Thermal Control Maneuvers	70
Cruise ACS	10
Breaking Burn	2455
Landing ACS	20
Landing Site Navigation	25
Descent	209
Total	2789

For some inexplicable reason they do the breaking burn with a solid rocket motor with 292 seconds of isp. Their maneuvering thrusters have 272 isp, and the terminal descent is done with 296 isp. With this reduced performance they turn 3492 kg at TLI into 1203 kg on the lunar surface.

They get the wet mass there by flying an Atlas V 401 on a 5 day minimum delta-v maneuver, and although that's just fine for cargo, it just means more consumables and radiation exposure for a human. The Falcon 9 has higher mass to LEO, but lower mass to GEO, but it's also 1/3rd the price, so let's stick with the 2585 kg that a Falcon 9 can throw direct to Lunar Transfer Orbit and use a decent storable propellant isp of 312 seconds. With that we can deliver 1038 kg to the surface.

With a inert mass ratio of 0.15 for the lander, the total payload mass is 651 kg. Using the crew/consumable mass above, and assuming 2.5 days to get there, we can spend 28 days on the lunar surface. Or you could try to fit in propellant to fly back.. I guess, if you wanna die in your bed or something.

Two Game Changing Technologies

2011-01-24T14:55:00.000+10:00

The Gravity Loading Countermeasure Skinsuit (yes, that's Richard Garriott) and Mini-Magnetosphere Radiation Shielding are two technologies which, if successful, will change the way you think about space exploration and eventually even colonization. They address the two fundamental stumbling blocks of long term missions in space: the negative health affects of zero-g and radiation exposure.

Zero-G Skinsuits exert a force on the wearer's body which duplicates the loading on the skeleton that gravity usually provides. The expectation is that Skinsuits will reduce or eliminate the deleterious bone loss that astronauts currently experience in zero-g. So far, the prototypes have only been tested on parabolic flights, although they are similar to the Russian penguin suits which were used by cosmonauts on MIR (unfortunately with little to no reported results - as is typical of Russian space medicine).

Should Skinsuits turn out to be effective at eliminating bone loss, and possibly even have some positive effect on muscle loss, this finding will render other technologies aimed at addressing the problem less important. Specifically, solutions aimed at getting astronauts to Mars as quickly as possible will be less important. Artificial gravity generation for long trips or even for space colony designs will be less important too. Although there may still be a use for weak fluid settling variations on the theme, not having to produce an Earth-like gravity field is a much easier engineering problem.

MiniMags produce an electric field around a spacecraft that interacts with the interplanetary plasma to produce a charge separation, strengthening the field. When ionizing radiation hits the electric field it is deflected and so does not cause damage to the spacecraft or its occupants. It was widely believed that such a "magnetic shield" of solar radiation could not be achieved without superconducting magnets and large power sources - placing it firmly in the domain of science fiction. However, a number of observations of solar wind phenomena and subsequent ground experimentation has shown that only a small electric field is initially needed - the neutral interplanetary plasma will do the rest.

Should MiniMags turn out to be effective at protecting spacecraft and human occupants from ionizing radiation they will solve perhaps the biggest problem with long term human exploration of space, and eventual colonization. Previously, the only known way to deal with the radiation problem was to surround the crew with mass. Over the years, a number of creative techniques have been devised to have the mass serve double duty - for example, using propellant or consumables mass to shield the crew. Careful study of the available materials for shielding has led us to determine that high hydrogen content materials like polyethylene are best, suggesting that the interior of crew cabins should be lined in the stuff, and windows should be replaced with periscopes (because ionizing radiation only travels in straight lines and is not reflected by mirrors). All these design problems go away with an effective radiation shield.

At the time of writing, neither of these technologies is being adequately funded. While the NASA Technology Roadmaps currently identify "pressure garment" suits as a potential avenue for research, they place it in the EVA-suit category and seem to be unaware of Skinsuits. MiniMags are not identified in the technology roadmaps at all.. This is particularly egregious as not only can MiniMags be used as a radiation shield, but they can also be used for in-space propulsion. As such, they should appear in both TA06 and TA02. But never fear! I've informed the Aeronautics And Space Engineering Board of this oversight and I'm sure they'll get right on it ;)

UFO Evidence (or the lack thereof)

2011-01-20T14:08:00.001+10:00

"I was on the beach, at the water's edge and looked to the west to see a beautiful, bright moon. Except it wasn't the moon! It was a bright light moving slowly east, towards me and surrounded by a swirling mist. The mist rotated clockwise around the bright, white light and followed it perfectly."

Harry saw something strange in the sky, so he grabbed his video camera and put it up on youtube. It's a perfectly reasonable thing to do, and plenty of other people do the same. You could say it's a defining feature of the society we now live in. Most of us walk around with a camera in our pocket. Many of us whip out our camera phones to take a picture of anything interesting, funny, or even just to later post on Facebook to show that we're out having a fun time.

As it turns out, this particular UFO was quickly identified as the second stage of the first Falcon 9 flight, spinning uncontrolled despite valiant efforts by the thrusters to correct the spin. It was the only flaw of an otherwise perfect flight. The video was shot just 122km from me, but I wasn't looking at the sky that morning, I was asleep.

Despite the identification, the comment section of the video (truly the last refuge of intellectual thought) remains alive with speculation and denials. Included in the discussion is comparisons to the "Norway Spiral", another UFO sighting later identified as caused by a wayward rocket.

If you search youtube for UFOs you will discover a lot of videos which are legitimately people seeing stuff in the sky they don't understand. Almost all of them are comically identifiable: helicopters, aircraft, balloons, planets, and even the International Space Station - unfortunately searching for passes of the ISS doesn't get nearly as much. Many others are so mundane that one wonders why anyone would post them, or the UFO is only seen after the fact (a pretty big hint that you're seeing a video artifact). But there's certainly no shortage of video out there of UFOs.

Unfortunately, NASA gets harassed by the crazies and perhaps doesn't provide enough ridicule.. but, of course, ridicule is the CIA's job.

Sigh.

How The Politicians Think

2011-01-14T11:12:00.003+10:00

If you have one of these, turn it off now

It's almost funny whenever a member of Congress opens their mouth and says something about NASA. Thankfully I don't pull my hair out or I'd be bald by now, it's just that funny. Here's a quick list of things I have to remember to make sense of US space policy.

"Heavy Lift" means super heavy lift. Whenever a politician says "heavy lift", or just about anyone talking about space policy, they mean a vehicle that can lift more than 50 tons to LEO. Actually, they almost always mean a Saturn class vehicle.. and in many cases they actually just mean the Saturn V. When someone who actually works in the space industry says "heavy lift" they mean heavy lift - a vehicle that can lift more than 20 tons to LEO but less than 50 tons. And they almost always are talking about actual vehicles that you can place an order for right now.

The workforce is precious, and capable and vital, except for when they're aging. Unlike every other industry in the world where new people are being trained and old people are being retired, and people who get sick of their boss go find someplace else to work or even change to other careers, aerospace workers are fixed in number and hold their jobs for life. Yes, apparently the aerospace industry is a 50s utopia where Dad makes rockets and although he's highly trained and very very intelligent, if he were to be laid off he'd have no choice but to go on unemployment or, worse yet, take a job driving a taxi.

The space program is a matter of National Security. Except when it's not. NASA doesn't make missiles... or do they? Most everything "made by NASA" is actually made by the prime contractors like Lockheed Martin, Boeing, ATK, umm... Lockheed Martin - and these same companies also make fighter planes, bombs and, yes, missiles. A more cynical person than me would say that it seems NASA's primary purpose is to funnel money to these companies to support their infrastructure for making weapons. If you continue to scratch this one it'll never heal.

Kids love space and we can use that to trick them into studying science, technology, engineering and math (STEM). Obviously, kids are stupid and we need them to be smarter so we can keep the workforce vital because if we don't we'll lose the next war. That's right, the National Security of the USA depends on whether little Billy is inspired by NASA's Moon mission (or whatever they're doing this week) to become an astronaut when he grows up. We have to make it really hard to become an astronaut too - you need at least a PhD, but two would be better, and you have to join the Air Force.. preferably both at the same time - and everyone who drops out will get jobs on Lockheed Martin and make ICBMs. Yes, that's what I said - the aerospace industry is populated by failed astronauts, didn't you know?

SpaceX is the only commercial launch company in the world! Competition? What's that? The Soyuz is run by the Russian government who are still communists, no matter what they say. The Ariane is a myth invented by the French. Atlas and Delta are owned by the Air Force and only launch military satellites, they have no interest in this whole commercial thing. There's no market out there for commercial spaceflight anyway. It's not like anyone has a 24,000-sq-m assembly facility where they're assembling private space stations. They haven't already flown two prototypes on commercial rockets. Boeing hasn't signed any deals with them to deliver crew. Commercial - by which we mean SpaceX - isn't ready to fly humans, they haven't even demonstrated the launch of a capsule, orbit and successful return to Earth - something only 3 countries have ever done before.

Space Tourism is not real spaceflight. Oh, we're happy to support the burgeoning suborbital spaceflight industry. We voted for that law which said that if someone signs a contract promising they won't sue that they actually won't be able to sue you didn't we? Then we signed that other one that said their families won't be able to sue you. We sent our reps to your openings and got behind building lots of spaceports around the country. We got you those tax cuts didn't we? What, we didn't? Oh, ok, but we're trying, and that's what counts. We love suborbital space tourism because it doesn't interfere with our pork, but it's not real spaceflight.. I mean, it's not like anyone has ever flown to orbit and spent a week or two on the ISS. It's not like every seat that has ever been made available has been sold. Who would pay $20M to $40M and take time out of their busy lives to go to astronaut training, just for that. There's just no market, and anyway, there isn't any seats available. What's that? 2013 you say.

Did I miss any?

Mars Direct Without Super Heavy Lift

2011-01-02T01:34:00.002+10:00

For a decade or two now the proponents of Bob Zubrin's Mars Direct have been bemoaning the lack of super heavy lift (any vehicle that can lift more than 50 ton to LEO). While few advocates claim a heavy lift launch vehicle is the only component of the Mars Direct plan which is missing, most consider it a necessary prerequisite.

Before I tell you why I think that's simply wrong, let's just make a quick list of all the other things we still need: decent life support, space suits for Mars, rovers that run on methane/LOX, the ISRU propellant production system, bigger entry/descent/landing systems than have ever been flown, portable field equipment for the science mission, artificial gravity generation, and the habitat itself. Oh yeah, and a space rated nuclear reactor.

The beautiful innovation of the Mars Direct plan was the use of the Mars atmosphere to produce the return propellant so it doesn't need to be carried all the way from Earth. Without this simple idea the size of the launch vehicle would have to be exponentially larger. The architecture is littered with examples like this. The use of direct aerocapture over aerobreaking or just using propellant to enter Mars orbit. The advance staging of the Earth Return Vehicle, etc. It's such a shame that this willingness to trade mission complexity for reduced launch capability has been be lost. So we sit on the ground, waiting for a big enough rocket.

Why can't we make do with the rockets we've got? Why can't we start now? While many of the technologies in the list above could be tested with the smaller launch vehicles we have now, it's hard to imagine how to develop the capability of putting 30 ton payloads onto the surface of Mars without first having the capability of throwing 30 ton payloads to Mars transfer orbit.

An LH2/LOX third stage, these days often called an Earth Departure Stage, with an initial mass of 100 tons in low Earth orbit, will do the job (dry mass 6328 kg). To get any smaller we need to start using multiple launches. The traditional approach is to send up the EDS and then send subsequent flights to fill it up. The primary difficulty with this approach is that the LH2 starts boiling off as soon as the sun hits it, so you have to get the propellant up there as quickly as possible.

I'd like to propose an alternative. Using a storable propellant would mean we could take as much time as we like to build the EDS but it would be more like 177 tons in low Earth orbit (dry mass 13359kg). While I'm going backwards, why stop? All that rendezvous and docking and propellant transfer is heavy and eats into the inert mass ratio, so amassing all this propellant is likely to be a slow process. How can we reduce it?

Most EDS designs call for more than just the one engine. This is because the entire burn has to occur in less than a few minutes to make the orbital calculations workable and avoid prolonged exposure to the radiation belts when sending the crew. If we're going to use multiple engines anyway, we could just use multiple stages firing in parallel. Of course, they'd have to be docked together pretty well.

Ok, enough stalling, how many flights do we need?

In just a few years, SpaceX will be fielding the Falcon 9 Heavy. It will be able to throw 32 tons to low Earth orbit. A storable propellant upper stage (dry mass 2226kg) can throw 5 tons to Mars transfer orbit and still give us 2.5 tons of propellant to perform rendezvous and docking with the other stages. A final flight is required to deliver the payload to the cluster of stages. As said earlier, these 7 flights can be stretched out over as long a period as is required. The total cost of each 30t Mars throw is $665M.

Compared to the reported $300M price for a launch of the proposed SpaceX super heavy lift vehicle, this seems like a pretty bad deal. The argument can no doubt be made that paying SpaceX $2.5B now and waiting for super heavy lift is a better idea. Remembering that SpaceX will be developing the Falcon 9 Heavy on their own dime, from a simple cost perspective, more than six flights of the super heavy lift vehicle have to be flown to justify the development costs - but more important than this, sitting on the ground and waiting is not the right choice.

Update April 12, 2011: Obviously SpaceX's announcement of the Falcon Heavy, which will take 53 tons to LEO and yes, they plan to develop on their own dime, completely changes the plausibility of this architecture. It is now conceivable to do just a few launches to build a big enough EDS. I still think storable propellant is worth the extra mass in LEO.. it's just more mature right now, and NOFBX in particular makes it even more viable.

I'm not questioning the virtues of LH2, but we need both development to reduce cryogenic boiloff and an increased flight rate before it will be a plausible technology. We should be doing this development, and supporting the launch industry to increase flight rate, but there is no reason to wait for either to be successful before we start lofting heavy payloads to Mars to demonstrate the techniques required on the business end of Mars colonization.

My 2010 Review

2010-12-29T15:28:00.002+10:00

I started this year thinking the Augustine committee had nailed the Moon shut. Considering that I was a proponent of Constellation before the Augustine committee, that's pretty significant. If I go back to that time and see what I was saying to people, most of it was explaining the flexible path as an alternative to sitting on the ground waiting for a booster and a capsule and a lander to be developed by NASA.

I end this year thinking that the Moon isn't nailed shut. SpaceX has demonstrated that making a capsule and booster need not be expensive. Armadillo Aerospace and the other contractor's work on Project M (now Project Morpheus) demonstrated to me that going to the Moon need not be expensive. Tim Pickens and the Rocket City Space Pioneers have successfully restored my faith that the Google Lunar X-Prize will be won. Paul Spudis has actually become a robotic exploration advocate! In a few years time it won't be absurd to suggest that a commercial effort could send a rover to characterize the polar ice, make money by selling data to NASA, and later start selling lunar derived propellant in orbit.

I don't mean to suggest this negates the need for heavy lift. Actually, quite the opposite. I mean this to demonstrate that my belief that lunar exploration was necessarily expensive is slowly going away. With that frame of reference, I have to admit that maybe my belief that heavy lift is also necessarily expensive may have to go away. SpaceX have suggested they can do 130t to LEO for $2.5B in development costs and $300M per flight.

But the other problem with heavy lift is that it's a gate keeper. The advocates are perfectly happy to say that the Moon (or any beyond Earth target really) is off limits without heavy lift. This is simply wrong. We don't need heavy lift to send rovers to Mars so I think it is pretty clear that we don't need heavy lift to send rovers to the Moon.

Humans weigh less than rovers.

The problem is the can't-do attitude.

Soonest Space Solar Power

2010-12-20T11:19:00.000+10:00

Space Solar Power has a bad rap, caused predominately by advocates who can't separate the exciting long term vision from the short term facts. In his recent paper, Al Globus has tried to rectify this by investigating what can be done with demonstrated launch vehicles, solar collectors and power beaming (and without on-orbit assembly, manned outposts, lunar materials, etc). His conclusion is that it appears space solar power is now ready for niche markets, such as forward military bases, where the price of power can be as much as $1/kWh.

The low cost launch vehicle of choice is, of course, SpaceX's Falcon 9. High specific power solar collection is achieved using thin-film heliogyros as demonstrated by the Japanese Ikaros satellite. The power beaming technology is infrared laser with custom solar panel receivers, as demonstrated by LaserMotive in their win at the Space Elevator Games last year.

A minor improvement in Globus' architecture is apparent. The mass of the spacecraft was estimated based on the throw capability of the Falcon 9 to geostationary transfer orbit (GTO), presumably because a solar sail style flight is expected to circularize the orbit, and solar sails can't start from low earth orbit (LEO). This is an implicit trade over a solar electric style flight from LEO, which I'm guessing is intended to utilize the solar collector for double duty in order to avoid additional mass. I'm not sure this trade wins. Even with a SMART-1 performance thruster, starting from LEO places 7751kg in GEO, 3.2 tons more than the estimated mass in the paper. If a NEXT thruster is available, the improvement goes up to 5.2 tons. However, this improvement only doubles the performance of the system, perhaps halving the price of power at the meter, which still doesn't make it competitive with the grid.

The problem is scale. Globus should be commended for describing a space solar power system that is achievable with current technology and could even make a profit in some niche markets, but let's think just a little bit further ahead for a moment. LaserMotive continues to improve the performance of their laser power beaming systems, so the 8% efficiency suggested may soon be on-par with the often quoted 10% efficiency of microwave power transmission. The paper suggests that SpaceX could reduce their prices by a factor of 3.6 if one ordered 1000 launches, but this claim is a few years old now. A more recent claim by SpaceX is that a super heavy lift vehicle could be built that delivers 130t to LEO for $300M per flight, a factor of just 2.3 - but the improved logistics of a single launch may offset that.

It should come as no surprise that reducing launch costs makes space solar power more feasible. What does surprise me is that sufficient specific power improvements in solar collection has been demonstrated which makes it reasonable to choose a lower efficiency beaming technique, with the resulting effect on the mass of the spacecraft making it launchable on existing boosters. This is a revolutionary idea which not only makes sense right now but defines a path for future work that will bring space solar power to the meter.

Non-Rotating Artifical Gravity

2010-12-16T17:07:00.004+10:00

If you put a long boom on a satellite, it will align to the "local vertical". This was first demonstrated on the GOES 3 probe in 1978. It works because the forces of gravity and the "centrifugal force" balance at the center of mass.

Today, long life space tethers are available, using existing materials they are light enough for long lengths to be launched on a cheap launch vehicle like SpaceX's Falcon 9. A length of 500 km, with a lifetime of 10 years, would have mass of just 1275 kg. The tether would stretch from the altitude of the International Space Station (~340 km) up past the altitude of the Hubble Space Telescope (~595 km), out to where the polar orbiting satellites do their job (~700 km+). Within equal masses on each end of the tether, a force of 0.1g would be experienced, with no rotation of the structure required.

Of course, this only works while in orbit around a planetary body. Around the Sun, say for generating artificial gravity for a trip to Mars, a much longer tether would be required and it quickly becomes infeasible. So what good is it? Currently, we have very little data on how the human body responds to partial gravity. Sure, we know lots about how it responds to 1g, and we have some ideas about how it responds to "zero g", but we don't have any data at all about anything in-between. 0.1g is just enough gravity for a human to stand upright and walk around (although Joe Carroll recently suggested that 0.06g was sufficient). If we could put some astronauts on a station with this level of partial gravity for a few months it would give us some vital data for determining whether people can actually live on the Moon or Mars or even asteroids for long periods of time without serious health issues.

Having the low end of the tether at the same orbit as the ISS, and having it not rotating around at high speed would make getting to the experiment very convenient. The high end of the tether could simply be the upper stage of the launch vehicle. SpaceX has already demonstrated that their second stage can be relighted, and flying to a circular orbit of 800km seems well within their capabilities. A 500km tether reel could fit in the trunk of the Dragon, which can remain connected to the second stage after separation.

Considering the availability and low cost of the hardware, the low risk of non-spinning artificial gravity, and the massive scientific payoff, NASA should be pursing this.. now.

A New Sputnik Moment?

2010-12-08T10:31:00.002+10:00

Stephen Smith has an post over at his blog questioning President Obama's rhetoric that the down tick in the economy is having the same effect today as Sputnik had on the USA in the 50s and 60s. He's not convinced and neither am I, but near the middle he asks an interesting question: What would be the equivalent of a "Sputnik moment" in today's world?

The shock in the US caused by Sputnik was not so much that it was a military threat - although it was - but that it was a significant technical feat achieved by what most of the western world considered a backwater of scientific thought. Today, there are many technologies that are slowly being developed around the world which are primed for a breakthrough. Earlier this year North Korea claimed a fusion power breakthrough which certainly would have been a Sputnik moment if it hadn't turned out to just be a claim about fusion bombs, not fusion power.

This highlights a very important part of the Sputnik formula: how does the protagonist country dramatically demonstrate their technological achievement so there's no misunderstanding and no way to refute it? Sputnik did this fabulously by broadcasting an unmistakable signal that could be confirmed by amateurs and professionals alike. Any attempt to put the genie back in the bottle with Sputnik would be met with howls from the populous.

Suppose some manufacturing backwater suddenly started turning out superb jet engines, or even a whole new fighter plane. Just as a matter of competitive interest, other manufacturers would no doubt arrange to get their hands on a few samples and check out their quality. I expect that more than a few "national security" inquiries would also be made. What they discover blows their mind: the fan blades, the compressor, the combustion chambers, even the cowling, are all made from materials they've never seen before. Parts of the combustion chambers even appear to be made of perfectly shaped diamond.

By releasing these products onto the market, the protagonist has demonstrated a highly functional molecular nanotechnology manufacturing system. This is a massive breakthrough, and it would be completely unexpected. The current state of the art in molecular nanotechnology is basically: designing stuff we can't actually build. Here's some examples done with the open source nanotechnology CAD tool NanoEngineer-1:

There has also been some interesting work done by Ralph Merkle and Robert Freitas Jr. into making a "tool set" that might some day be usable to slowly make small objects in single quantities using hydrogen and carbon.

If some backwater country was to demonstrate that they had a molecular manufacturing system that could build anything they can design, using a handful of atoms - aka, not "just" a hydrocarbon metabolism - and do so on the macro scale, it would instantly make them a super power and set the stage for a worldwide scramble to duplicate their efforts and come up with some reasonable defense. I could imagine immediate calls for non-proliferation of the technology, etc.

That would be the equivalent of a "Sputnik moment" in today's world.

Apollo 8 Solo

2010-12-03T16:24:00.002+10:00

In 1927 Charles Lindbergh flew non-stop from Long Island to Paris. He was catapulted to instant fame by doing so and won the Orteig Prize. He didn't have a co-pilot. He didn't have an army of engineers monitoring his plane or a flight surgeon monitoring his heart rate, it was just him and his trusty single-engine monoplane, the Spirit of St. Louis. His achievement is heralded today as kick-starting the commercial aviation industry and opening up the skies to the everyman.

But what of space? Could a modern Lindbergh fly an impossible journey and change the way we look at spaceflight forever? I think it can be done, and for cheaper than you might imagine.

In 1968 the first humans left the vicinity of Earth, flew 6 days and nearly a million miles to the Moon and back. Their mission not only was the first, it also proved the feasibility of the missions to follow. Apollo 8 would have been much easier to achieve had they only wanted to swing-by the Moon, and still a significant achievement. Instead, they entered lunar orbit, circling it 10 times before returning home.

If the flight is to be attempted today, the cheapest available launcher is the Falcon 9 from SpaceX. It can put 10,450kg into LEO. The Dragon capsule is also available - they say the crew configuration is not much different from the cargo configuration - and after removing the 310kg Common Berthing Mechanism, and another 60kg of miscellaneous mass savings, a dry mass of 1926kg is achievable.

For a single crew member, assumed to be less than 90kg, the consumables requirements for one week are: 11.839kg cabin air and pressurization, 25.83kg oxygen candles, 52.71kg LiHo CO2 scrubbers, 45kg food and water. Adding this to the dry mass gives a final mass to run the rocket equation on: 2152kg.

The delta-v required to leave Earth orbit and head towards the Moon is a whopping 3107m/s. Entering low Lunar orbit requires another 837m/s, and returning home requires another 837m/s. So we need a grand total of 4781m/s.

All the propulsive maneuvers are achieved using the Draco thrusters on the Dragon capsule, which I estimate to have a specific impulse of 309 seconds. dv = 9.8 * 309 * ln(10450 / 2152) gives us an uncomfortable 4m/s of margin. :) [edit: it occurs to me that the Dragon dry mass already includes a life support system, and a 78.54kg reduction in mass has a massive effect on delta-v. So this is more like 115m/s of margin, which should make anyone happy.]

In order to win the Orteig, Lindbergh had the Spirit built custom for his needs. Benjamin Mahoney is said to have built it for cost. Perhaps Elon Musk could be similarly persuaded, but at current prices it'll cost around $130M.

I Guess "It's Not Junk" Is Just Too Visionary

2010-11-28T17:29:00.002+10:00

Last week I attended a different kind of space conference. It was populated with very intelligent people who are active in doing "real" space, working payloads to get them accepted to fly on government vehicles - often up to the International Space Station - or as free flying satellites. I recorded 17 videos of the event, which I found enthralling, but I'm weird like that.

The best talk (in my opinion) was given by Dr Alice Gorman of Flinders University (Australia) about achieving an international agreement on Space Heritage. The presentation was aimed at preserving historic sites related to human spaceflight so that future generations have some physical connection with the past. This is something we do well in Australia, with "heritage listing" enforced by law. Of course, there's not that many sites that one might consider space heritage in Australia, a few radio telescopes that were used during Apollo - one that has already been heritage listed - but that's about it. The presentation went on to suggest that objects in orbit and on the surface of the Moon deserve as much respect as objects on the ground and the international agreement being sought was on how to define a "heritage site" that is off the Earth.

After the talk, some rather pointed questions were asked, and some rather pointed answers were given, then we broke for coffee. Over biscuits I stuck my head into a conversation with a PhD from Australia, another PhD from Europe and the head of a Japanese space company - his major objection was the use of the words "common heritage of all mankind" in the discussion of space heritage and all of a sudden I was feeling at home.. I expected to hear the old arguments about the United Nations Convention on the Law of the Sea, and the International Seabed Authority.. and I wasn't disappointed. What soon followed was some discussion about the private ownership of celestial bodies and yadda, yadda, yadda, you've heard all this before right?

In a way, it's nice to know that the "smart kids" are having the same conversations as the rest of us.. in a way. An argument which hasn't completely entered the standard model just yet is the suggestion that recycling satellites, spent propulsive stages and other sorts of "space junk" may be a critical part of a future space-faring civilization. No doubt, my presentation of the argument was probably a little rough, but I was surprised to lose just about everyone after the first breath. The fellow Australian was the first to break the silence suggesting that "it's going quite fast you know" as if I had just suggested the use of warp drive to catch the attention of a passing Vulcan spaceship.

Perhaps I shouldn't have labored the point, but I couldn't help myself. I started talking about the delta-v requirements of deorbiting GEO junk vs placing it into a super-synchronous graveyard orbit.. their eyes glazed over. Really? I'd just listened to four hours of ISS payload integration, the difficulties of sterilizing seeds for export, space weather detection, etc, and a little orbital mechanics is too boring?

This isn't the first time I've heard people scoff at the notion of recycling already on-orbit assets. At the New Space conference back in July a number of people said they had switched off when one of the panels started talking about it, as "they clearly don't understand orbital mechanics". It's frustrating. I don't claim to be an expert on the subject, but having actually done sufficient study (and written code) to calculate trans-lunar injection and other maneuvers, predict the trajectories of asteroids, and even change them to be more favorable for human missions, I really can't see what's so wrong with the idea of recycling valuable space assets.

If you're living in a space colony in GEO, it seems obvious that you would take whatever mass you could get for free, especially if it is highly refined solar panels and other materials. If you're living at one of the Lagrangian points you'd have to have vehicles capable of 4 km/s of delta-v and a steady supply of propellant or the means to produce it from water stocks, why wouldn't you go scavenging in the graveyard orbits for tanks and rocket nozzles to keep those vehicles operational without paying for expensive replacement parts from Earth?

Although I appreciate and respect the practicalities and even the horse trading of real space, I don't think we need to close our minds to future possibilities, as the decisions we make today, with good intentions or bad, will make that future.

The Space Industry

2010-11-15T10:41:00.001+10:00

Here's a great video by Bob Stover, Tim Walters and Todd Halvorson.. one of the best I've seen.

Thoughts on a SpaceX Lunar Architecture

2010-10-07T17:35:00.005+10:00

It's no secret that the SpaceX Dragon capsule has a very impressive heat shield believed to be capable of direct lunar return. Official statements from SpaceX that they intend to add deployable landing gear and leverage the thrusters in order to land on land in the future prompts an obvious suggestion: if it can land on Earth, could it land on the Moon too?

The Dragon capsule has thus far been launched on the Falcon 9 booster, and although that booster is able to put 2473kg into lunar transfer orbit, after using the Draco thusters on the Dragon to enter low lunar orbit the total mass would be under 1876kg.. this seems a bit light for a crewed configuration, especially when you consider that only 1422kg of it could be returned to Earth. And that's just lunar orbit.

We need a bigger rocket, and the official SpaceX plan right now is called the Falcon 9 Heavy. One should not be confused by the name, the F9H is not "heavy lift" in the sense often used by space advocates and policy makers - who should more correctly be using the term super heavy lift. So how heavy is the F9H? Comparison is usually done in terms of lift to LEO, but for our purposes lift to LTO is more interesting at 10622kg. A slight improvement on the Delta IV Heavy at 9984kg.

Now we can imagine a Dragon-lander flying direct from lunar transfer orbit to the surface, it would have a mass of 3766kg when it landed which is quite respectable. For a cargo flight this is fine, delivering 2737kg of payload, but it's unlikely the vehicle would have enough fuel left to attempt an ascent.

Having determined that a single stage direct descent vehicle is unlikely, we're now forced to choose a mission mode. The size of the launch vehicle has already dictated that LEO should be bypassed, so our choice comes down to lunar-orbit rendezvous (the mode used by Apollo) or lunar-surface rendezvous, aka, refueling on the surface. So much has been said about LOR already, so let's run the numbers for LSR.

Having landed a crewed Dragon-lander on the surface, and assuming no fuel is left, we would require 6014kg of propellant to return to Earth. This is not too bad, at 3 fuel landings, but we can do better. If we can carry just 540kg of fuel in reserve we can eliminate the third fuel landing. Another alternative is to throw 338kg of payload out.

Of the 2737kg payload delivered, we have to determine how much is needed for the crew and their supplies, and how much can be fuel. The pressurized volume of the Dragon is 10m^3 requiring 11.839kg of air to fill. Without an airlock we may wish to cycle that a few times, so let's say 118kg total. Next we need a one week supply of oxygen candles at 25.83kg per person, and LiOH to scrub the CO2 at 52.71kg per person. Finally there's food and water at 45kg per person. For a total of 488kg for a crew of three. Too easy! This leaves 1708kg for spacesuits and equipment.

Once on the surface, the crew would vent the chamber, get out and refill the fuel tanks. Having gravity, transferring the propellant is well understood. Return to Earth would be direct, with no need to enter lunar orbit or perform a rendezvous. As no parts fall off the Dragon-lander on the way it could be fully reusable, providing a stepping stone to in-situ produced propellants.

I estimate a Falcon 9 Heavy / Dragon-lander cargo configuration would cost around $40k/kg to the lunar surface. With the two fuel emplacement flights, this makes crew transport something like $130M/seat for crews of 3, but you could conceivably get that down to $55M/seat if you were delivering 7 at a time - most likely to some kind of base as they would have reduced volume for equipment.

Most of my calculations were done with this rocket equation calculator and I used an inert mass fraction of 0.15 for the lander.

Revolutionary Thinking in Nuclear Rockets

2010-10-02T20:56:00.001+10:00

A few months ago I started talking to Jim Dewar about his latest book, which I reviewed in August. My suggestion to him was that he needs to write a better introduction that assumes the technical knowledge of rocketry but not the nuclear industry. He took on the task and recruited a number of people to serve as reviewers, myself included. So far, it hasn't been published anywhere, but he's given me a copy and invited me to publish it here.

To avoid confusion, I've put it on my website:

A Technical and Economic Introduction to Nuclear Rockets

It's long but divided into sections, and I think Dewar has done a great job, so check it out.

Jim tells me he would like to hear feedback.

Affordable Deep Space Exploration

2010-10-01T12:46:00.002+10:00

For too long the aspirations of NASA have not matched the budget allocated. Building the International Space Station has been a decade long effort, now finally reaching completion, and until just recently the plan was to splash it into the ocean before moving on to "the next thing". For a while, that was a return of humans to the Moon, but the recognition that the necessary budget would not be forthcoming has pushed that goal so far into the future that it doesn't even make much sense to talk about it anymore.

Today, the focus is on making a new heavy lift vehicle, finishing a big heavy capsule to go on it, and considering the possible missions that could be done with that hardware should it ever be finished. At the same time, technology development and commercialization of ISS resupply promise to free up some existing budget dollars to pay for the lunar landers and prepare for the next next thing: Mars.

This has prompted many to ask: what if we didn't need heavy lift? What if NASA could do deep space exploration without it? I know what you're thinking, propellant depots, right? Not this time. I've talked about propellant depots, enough, let's talk about something completely different.

In this paper David L. Akin has made the case for ISS crew rotation, two lunar missions per year, and a "flexible path" mission every second year, using only storable propellant stages and the existing Delta IV Heavy. He's done the sums and says the whole thing could be done for less than the current NASA budget for human spaceflight.

Here's how it works. First off, the Delta IV Heavy (or some similar launcher should it become available) needs to be human rated. That's expected to take $2B and 5 years. A five ton crew module is developed - it's about 70% larger than the Soyuz - for $2.5B. With just these two components ISS crews can be rotated and this will likely happen anyway under the commercial crew development program. One thing to keep in mind, though, is that the heat shield has to be able to do direct reentry from the Moon, something only the SpaceX Dragon and the Orion is planning at this time.

Simultaneously, an Orbital Maneuvering System is developed. This is similar to the service module on most crew spacecraft, in that it uses storable propellants and is expended after use. A common configuration is used for multiple maneuvers: lunar orbit injection, lunar descent, lunar ascent and trans-Earth insertion. A modification of the Orbital Maneuvering System is required to do the final landing on the Moon. Landing legs need to be added obviously, deep throttling and possibly restarts will need to be supported. These changes are significant enough that it deserves a new name, so Akin calls it the Terminal Landing Stage.

And that's it. The paper explains a few of the more interesting details. For example, for non-ISS missions LEO is completely bypassed, with direct lunar injection of the stages. All the rendezvous and docking happens in low lunar orbit, and by careful management of the loading of propellants stages, can be fired sequentially to generate the necessary delta-v for each maneuver - there's no need to transfer propellant from stage to stage.

Peak funding comes at the end of the development of the program (where it belongs!) and is less than $3B/year. Yes, that's right, Akin says we could have ISS crew rotation, 2 lunar missions a year and a flexible path mission every alternate year for less than what was being spent on the Shuttle program during it's peak. That's the value of leveraging existing hardware.

Read my lips: no new launch vehicles.

* Thanks to Ralph Buttigieg for sending me this very interesting paper.

Mining The Moon: Closing The Business Case

2010-09-18T15:38:00.001+10:00

I recently read Platinum Moon by Bill White, in just 4 days, it's just that much of a page-turner. Clark Lindsey has written an extensive review, which is mostly positive but has this little dig at the end:

A kilogram of pure platinum today sells for something like $53,000/kg. On the Moon even rich PGM ore would have have to be extensively refined to get anywhere close to that purity. A kilogram of raw ore would be worth a tiny fraction of that.

Until there are fully reusable vehicles flying frequently enough to LEO to bring costs there down to the low hundreds of dollars per kg, it's difficult to see how space mining can even begin to be viable.

My first reaction is to suggest that obviously high purity enrichment of platinum should be done on the Moon, and only "pure platinum" returned to the Earth - but I should first point out that Platinum Moon made the realistic argument that lunar platinum would be worth a lot more than market value in the form of commemorative coins and other trinkets - at least initially.

Extraction of oxygen from lunar regolith is a critical part of the plot in Platinum Moon and it's not unreasonable to expect a platinum enrichment facility to be capable of doing it as a side process. Similarly, extraction of aluminum from lunar regolith is an easy process which would also be available. Spinning that aluminum into tanks is simple manufacturing that could be done in-situ, and during lunar night the oxygen would naturally liquefy to make filling easier.

The landing vehicles in Platinum Moon use the fuel RP-1, a form of kerosene which is often approximated as dodecane in chemical formulas - this means it has 12 carbon atoms and 26 hydrogen atoms per molecule. On the Moon, carbon is about as rare as hydrogen, and the biggest deposits are in cold traps at the lunar poles. A simpler hydrocarbon, with higher performance, is methane with just 1 carbon atom and 4 hydrogen atoms. Liquid hydrogen could also be used as a fuel for a reusable lander. It seems inevitable that a complete propellant production plant - both fuel and oxidizers - would be an early infrastructure goal of an operational lunar platinum mine, but it would likely be separated from the mining and refining sites; requiring suborbital hops to refuel.

Estimating the size of a propellant production facility is difficult at this time. Current NASA estimates for a "pilot demonstration" plant to produce oxygen from lunar regolith are in the ~300kg range, producing up to 500kg/year. A similar sized plant in a cold trap could be expected to produce thousands of times as much, and would more likely be bound by the availability of tanks; which I imagine being transported from the distant platinum enrichment facility.. whether local production of tanks is more efficient depends on the flight rates.

Sticking with the "gateway" architecture presented in the book, lunar production of both fuel and oxidizer is game changing. Launching fuel for Earth departure stages from stockpiles on the lunar surface, via EML1, is cheaper than launching from Earth's deep gravity well. Storage of cryogenic propellants in the cold traps of the Moon until needed brings just-in-time delivery economics to spaceflight. This would allow the launch of larger processing plants and more sophisticated mining vehicles that can increase the production in a virtuous cycle.

If one could obtain pure platinum from the surface of the Moon, would it be profitable to return it to Earth at current market prices? I've previously shown that the SpaceX Dragon has a downmass of 3000kg at $28,330/kg, returning pure platinum from LEO at a profit of $24,670/kg. With the architecture described, cislunar transport is essentially free, but to make a profit, the initial costs of the architecture have to be amortized over every kg returned.

If the architecture costs low billions to setup then around 100,000kg needs to be returned over several years. For comparison, only 239,000kg of platinum was sold in 2006. The initial premium for lunar platinum would quickly fall to market levels, but would the market value of platinum fall significantly thereafter? I have had long arguments over whether or not platinum is an elastic market that is significantly effected by the opening of a new mine.. it's simply not clear what the demand for platinum is because the supply is so low at present, but it should be clear to see from the growing price of platinum over the years that more and more demand is out there for a very limited supply.

Some Retrospective Space Policy

2010-09-11T18:51:00.002+10:00

It's been a while since I said anything about space policy. This is primarily because the whole ball of wax can be summarized as, well, a big fat mess. As many of you are likely aware, I was an avid viewer of the Augustine committee when it was on, all 37+ hours of it, and still think they did a fantastic job with what they had to work with.

However, in retrospect, I think Norm Augustine hit the nail on the head when he started talking about "blue plate" options vs the alternatives that stuck within the existing NASA budget. I bet if they had to do it all over again they would have changed the balance to include more of the affordable options and less of the blue plate options.

Perhaps they could have worked out the completion dates and total prices of the various components of Constellation program under the "restricted" budget (aka, the "real" budget) including the options of splashing the ISS in 2015 and without. As Augustine himself said "ongoing programs should only be changed for compelling reasons".

From there they could have easily made the case that doing the booster and the capsule before starting work on the lander was a prudent course of action, and suggest the missions that could be done in that time.

The policy makers would have clearly gotten the message that the Flexible Path isn't an alternative to surface operations, but a prelude.

Commercial crew would not have been seen as a threat to the "government option" but as an enabler to moving budget away from routine servicing of LEO and into the exploration architecture.

And technology development could have taken its rightful place as the great hope that the exploration architecture could someday be accelerated from its plodding schedule.

But, as they say, hindsight is 20/20.

Engineering An Asteroid Close Approach

2010-09-04T17:03:00.002+10:00

I've been posting lately about the threat large asteroids pose to Earth, human missions to smaller asteroids, and the opportunities that will exist in the next few decades to do so. Up until this point, my analysis has been mostly for my own education and amusement, but I'd like to make a suggestion now which I haven't seen published in the literature or seriously discussed in either NASA working groups or even in the space advocacy community.

I'd like to suggest that we need not wait for an appropriate asteroid to come within range of Earth and plan human missions around just those opportunities - we can engineer a perfect close approach.

Next year, at the start of June, the asteroid 2009 BD will pass within the orbit of the Moon. Even though it is not a rare occurrence, few opportunities such as this have been identified, and realistically, no-one is going to be ready to send a human mission to an asteroid for years to come.

It seems a shame to let this close approach go to waste, with just 40m/s of tweaking, the orbit of 2009 BD could be changed to this:

(click to open the viewer)

The blue part indicates the part of the orbit which is within 20 lunar distances of Earth: over 965 days in the next 6 years. The delta-v required to change the orbit of this asteroid could be delivered by a single impulse, and the most advanced technology available to do that is to simply run into it.

Calculating how to change an asteroid's orbit has been an educational exercise which would not have been possible without the JPL Horizons system and the SPICE toolkit.

Rusty Schweickart Explains The Asteroid Threat

2010-09-03T10:29:00.000+10:00

I don't think he's given a better lecture than this.

Rock Envy

2010-08-25T12:40:00.004+10:00

With the exception of Hayabusa, all asteroid missions to-date have been to targets bigger than 1 km in "spherical radius".

Date	Encounter	Asteroid	Radius (km)	Spacecraft
1991	Flyby	951 Gaspra	6.1	Galileo
1993	Flyby	243 Ida	15.7	Galileo
1999	Flyby	9969 Braille	~1	Deep Space 1
2000	Flyby	2685 Masursky	~8	Cassini
2001	Landing	433 Eros	8.42	NEAR Shoemaker
2002	Flyby	5535 Annefrank	2.4	Stardust
2005	Sample Return	25143 Itokawa	0.165	Hayabusa
2006	Flyby	132524 APL	~1.1	New Horizons
2008	Flyby	2867 Šteins	~2.8	Rosetta
2010	Flyby	21 Lutetia	95.8	Rosetta

This has led a number of people to express dismay that all the asteroids which have been identified for human exploration missions have significantly smaller estimated sizes.

Date	Asteroid	Radius (m)
2016	2008 HU4	~5
2017	1991 VG	~45
2019	2008 EA9	~6
2020	2007 UN12	~4
2025	1999 AO10	~35
2026	2008 JL24	~2.5
2028	2006 RH120	~2.5
2029	2000 SG344	~22.5

Notice that the scale has changed from km to m. Of course, exactly why these rocks are small is most probably what makes them optimal for a human mission. Their close approaches to Earth most likely would have ended long ago if they were any bigger. Collecting samples from these asteroids will help us to understand why they are not in the main asteroid belt, which is very important to know as their larger cousins threaten the Earth.

Some mission planners at NASA and elsewhere have expressed a desire to exclude any target with a radius smaller than 25m, being referred to as "mere building sized" asteroids. This reduces the targets in the table above to just two, although the last typically scrapes by due to a lack of options. Exactly why this policy is being suggested is unknown. Some speculation includes:

the belief that more targets will become available with greater funding directed to finding them, so it's best to downplay the available targets.
the difficulty of approaching a small rapidly spinning body.
lack of mass for sample collection.
lack of surface area for exploration given extended mission duration.
overall "spectacle".

These are all terrible reasons, and I'd hate to be accused of putting up a "strawman" to knock down, but they are the only reasons that I have read about. If you've heard more, let me know.

The first reason is just bad politics, and it's completely unnecessary. No-one can reasonably say the asteroid surveys are getting "enough" money, but they're certainly getting some, and they're getting valuable priority time on telescopes, both optical and radio. Hopefully this is just an ugly rumor.

Approaching a spinning body is something astronauts have done before. Dale A. Gardner and others used the Manned Maneuvering Unit (aka, the astronaut jetpack) to match rotation with satellites in LEO to return them to Earth on the Space Shuttle. With this in mind, it would seem engineering and astronaut experience is more applicable to small spinning bodies than it is to large ones.

The lack of mass argument should be immediately recognized as a failure of imagination. Referring to these asteroids as "small" in the first place is suggestive of this. The smallest asteroid on the list above has an spherical radius of ~2.5m, about the size of this:

The biggest asteroid on the list above, 1991 VG, is about half the size of this:

And unlike these reference objects, asteroids are solid with few to no internal voids. So there's plenty of mass, and when it comes to surface area and mission duration, I actually think making the case for short mission duration makes a lot of sense, and besides, suggesting that just a few days is too much time to spend exploring one of those London bus sized objects is just silly. A meteorite of such a size would be investigated for years.

In regards to spectacle, I recommend watching the video I linked to above of Dale A. Gardner catching that satellite. Even with a London bus sized object you're in for one hell of a show.

Early vs Late Human Missions To Deep Space

2010-08-24T08:44:00.001+10:00

Anyone who has enjoyed my recreational attempts at designing a human mission to a near-Earth asteroid should check out the newly released mission to an asteroid by a team at Lockheed Martin*. The report ends with these important words:

The Plymouth Rock study shows that the first visits to asteroids can be easier and earlier than we have previously thought. The United States does not need to wait for more advanced technologies or develop expensive dedicated deep space vehicles. We can explore the asteroids within a decade, using spacecraft already being developed and tested.

This is a reasonable statement which I agree with. As far back as Apollo the question of "are we ready?" has been asked, and despite the success of Apollo it is still being asked. I have tried to make the argument that a Dragon capsule would be sufficient for a bare-bones mission to an asteroid, assuming some modifications to life support systems, dual use of propellant and supplies as radiation shielding and a whole lot of vigorous hand-waving. This Lockheed Martin study makes the same argument, obviously using their own hardware, and with a level of detail and rigorous breadth of study that puts my amateur efforts to shame. If we don't go we'll never be ready.

That said, they make some statements that go a little further than I have previously, or probably would. For example, consider this statement, which at first blush seems to be making a purely technical argument, but is certainly saying something a little more rhetorical.

As a consequence of their orbital similarity to Earth, there are only a few opportunities per decade to visit known asteroids. The number of opportunities will likely increase as more asteroids are discovered, but for now the limited number of opportunities has profound implications for asteroid mission planning.

It drives the timing of a human asteroid program since it may not make sense to plan a program which provides an initial operational capability during a period such as 2021-2024 when there are no known mission opportunities.

The small number of opportunities means that it may not make sense to design a spacecraft system dedicated to asteroid missions. Rather, asteroid missions would be performed occasionally by spacecraft that are also designed to perform other missions, such as going to the Moon or other deep space destinations.

While I can't find fault with the logic, I think I see a deeper message here. The second paragraph, while representative of a simple fact that I too was surprised to discover in my Prospector's Skymap efforts, is unnecessarily vague about what, precisely, it is recommending. I don't think it is saying NASA should not bother to field an asteroid mission until 2025, as is the President's current plan. This paragraph meant to hint that NASA should hurry up, perhaps even aim for the (2008 HU4) approach in 2016, the year the Senate's proscribed heavy lift vehicle is supposed to come online, lest the schedule slip and slip into the 4 year "asteroid gap".

The third paragraph above, however, is an outright stab at supporters of technology development, and is the "take home" message - going to the near-Earth asteroids is not a technology development program.

Bob Zubrin of the Mars Society recently made this argument in a little more alarmist way - it would be a terrible thing if VASIMR and propellant depots became "gateway technologies". The fear is that missions to deep space targets, Mars obviously being the intention, will be delayed until these technologies come online. "We can't go to Mars because we don't have VASIMR yet" they'll say. Unfortunately people are saying that, and the Plymouth Rock study comprehensively shows why it is not the case, at least for 6 month asteroid missions.

However, buried in the technical detail of this study is the answer why NASA is not yet ready to go all the way to Mars with existing technology and vehicles currently under development. The delta-v requirements are bigger for Mars missions than near-Earth asteroid missions, this is true, but the technology development required for a bigger Earth departure stage is minimal - with or without heavy lift. To see the real need for technology development we have to turn to page 13 of the report, and the section titled "Mission Duration".

Unlike Apollo or the Space Shuttle, the Orion spacecraft includes design features which support long missions, such as solar arrays rather than fuel cells for power, and regenerative amine beds rather than single-use lithium hydroxide canisters to remove CO2. Orion is designed to support four astronauts for 18 days going to and from the Moon, with a 180 day unoccupied period in lunar orbit while the astronauts are at the lunar outpost, plus 30 days of contingency loiter capability for a mission extension. This built-in long duration capability is a critical enabler for an asteroid mission.

Orion hardware is already designed for the same mission duration needed for an asteroid mission, addressing issues such as reliability, leak rates, hardware radiation tolerance, and micrometeroid protection. Micrometeroid and orbital debris (MMOD) protection has turned out to be one of the most challenging requirements to meet for long duration missions, since longer missions have higher cumulative probability of impacts.

The duration of a Mars mission is more like 32 months - 8 months there, 500 days on the surface (or, for a Phobos/Deimos mission, in orbit!), and 8 months back, and the crew size is almost certainly going to be bigger than an asteroid mission. The next section on "Life Support" addresses this.

Despite Orion's long duration capability, a five to seven month mission requires more food, water, oxygen, and nitrogen than Orion is presently designed for. Reducing the crew size from four to two astronauts and pairing up two spacecraft quadruples the number of days the astronauts can be supported, to approximately 80 days. A further factor of 2 to 2.5 increase in consumables is required for a 6 month class mission.

And goes on to state that although the Orion's open-loop life support system is adequate and the right choice for 6 month duration missions, it acknowledges that it is on the knife's edge and a closed-loop life support system is inevitably going to be necessary for the much longer duration missions.

Finally, no discussion of deep-space human missions is complete without addressing the radiation exposure problem. Section 10 on page 32 takes the problem head on and contains a great summary of the analysis Lockheed Martin took in the placement of components in the Orion spacecraft to provide good coverage for radiation shielding without adding additional mass. It also advocates an on-need strategy for deployment of supplies as additional shielding in the event of a solar storm. Flying asteroid missions is suggested as an important precursor to a Mars mission, and on this criteria alone that's a good argument.

In short, I think there's a false choice here. Although I agree with the basic statement that NASA doesn't need to design a dedicated vehicle now, and doesn't need fundamentally new technologies to reach the more favorable near-Earth asteroids in early missions, a sustained technology program to improve capability will widen the choice of near-Earth asteroids that are favorable and beat the path to Mars.

* If it's not already up there it should be soon. Thanks to Josh Hopkins for an advance copy of the report.

Smacking Asteroids For Resources

2010-08-19T18:02:00.014+10:00

Video by Eric Brueton

Summer studies of space settlements by Gerard O'Neill and NASA in the 70s and again in the early 90s both determined that significant amounts of mass is required for passive radiation shielding. Although structurally, most designs call for refined steel, it has been suggested that mass for the shielding could just be raw lunar regolith, left-over slag from future on-orbit industrial processing, or obtained from the asteroids. The asteroids are seen as preferable as, in terms of delta-v, they are most easily available. The typical argument is that a long duration mission to rendezvous with a near-Earth asteroid or comet (collectively, near earth objects, or NEOs) could skip a lot of launches from deep gravity wells, either digging into the NEO or
dismantling and processing it to make a nearby structure, or both.

The wrinkle, however, is in that "long duration" part. In terms of delta-v, there are NEOs which are easier to hit than the Moon, but all currently known NEOs require months to year long travel times. This rules out manned expeditions for the time being, as long duration human spaceflight beyond the Van Allen radiation belt requires significantly more shielding than Apollo style short term missions.
To break the stalemate, many have suggested the use of autonomous or teleoperated spacecraft to develop a soon-to-be Earth Hill-sphere crossing NEO into a life sustaining capable radiation bunker. As many appropriately sized NEOs cross within 2 or 3 lunar distances (LD) of the Earth, it's clear that only a short term mission is required to "jump on board" and bunker down. With adequate prediction of the NEOs orbit, resupply could be successfully staged ahead of time on slower, more energy efficient, trajectories.

When considering the risk involved in such an adventure, and the market opportunities of any such settlement, Earth or Moon orbiting alternatives start to sound a lot more attractive. So let's consider an orbital habitat that is closer to home.

To get mass from the surface of the Moon into an appropriate orbit, it is suggested, one can use a solar powered mass driver. The immense cost of building a lunar mass driver is quickly amortized over every kg of steel and regolith launched and the sheer quantities of mass required - 150,000 kg for the torus designs, 42,300,000 kg for the cylindrical designs, and that's just the structural mass (steel), for shielding it's 9.9 and 23.3 million tons of regolith - mass drivers beat rockets hands down. But building a mass driver of that scale, and all the infrastructure required to supply it with regolith and power is another roadblock. When people talk about it, I suggest that by the time those quantities of regolith are available from lunar industry there will be tract housing available there anyway.

Do we have to rule out NEOs for shielding of Earth or Moon orbiting space settlements?

Recently, the asteroid 2010 AL30 flew by Earth, closer than the Moon's orbit, traveling at a relative velocity of 9855 m/s. Approximately 10-15 meters in size, it is estimated to be one of nearly 2 million such objects in near-Earth space. On average, an asteroid of this size passes within a lunar distance once a week. Asteroids come in a variety of different types and densities, but on the lower end of the spectrum (2.6g/cm^3), 2010 AL30 would have a mass of at least 2,600,000 kg.

Capturing small asteroids like this in Earth or, better yet, the Moon's gravity is a difficult proposition. For the altitude that 2010 AL30 was traveling at, it would have to lose 8139 m/s of velocity to enter a circular orbit. Suppose we were to send a spacecraft to hit it head-on. The most recent example of an impactor in near-Earth space was the LCROSS mission, impacting a crater at the lunar south pole, it delivered a 2305 kg Centaur stage at 2700 m/s. If we take that velocity as representative, we would require our spacecraft to have a mass of 7,929,037 kg.. unsurprisingly, we require a bigger rock to slow down the smaller rock.

A better question might be, how big of an asteroid can we capture by head-on impact with a Centaur stage? Again using 2700 m/s as a reference, you'll find the asteroid can be no more than 756 kg in mass, which converts to an asteroid 66 cm on a side using the same density as before.

LCROSS was launched as a secondary payload on an Atlas V 401. The Centaur provided the entire burn, although there was a small amount of gravity assist provided by the Moon. The shepherding spacecraft followed the Centaur into Cabeus crater as the Moon is quite a hard target to miss at that range, but I can imagine a similar spacecraft avoiding the brunt of the impact of intercepting an asteroid. If the
spacecraft is equipped with a solar powered propulsion system, be it Hall-effect thruster or an electrostatic ion thruster (as used on the Deep Space 1 spacecraft that did a flyby of a comet) or even a mass driver, it is conceivable it could rendezvous with the various fragments, assemble them into a whole and shepherd them to another intercept.

As the shepherded mass grows, larger asteroids can be intercepted.

Such a spacecraft could also find purpose cleaning up more traditional
orbital debris.

Note: I wrote this a while ago, but forgot to post it, I'm not terribly sure of the math anymore. It seems about right, but I know now there are lower delta-v asteroids that wiz by the Earth within a lunar distance. But it has some good references.

Prospector's Skymap

2010-08-19T09:28:00.020+10:00

There have been over 535,000 asteroids discovered to date and they're all different. Some 7,121 of them are known to cross the orbit of the Earth and so are referred to as the near-Earth asteroids. If you're interested in flying a robotic mission to an asteroid, you need some idea of how much delta-v your spacecraft is going to need. I've written on this before. However, if you're interested in flying humans to an asteroid, you also need to know how long the round trip is likely to be.

To answer this, one needs to know both how far away the asteroid is at closest approach to Earth, and for how many days it will remain that close. To the interested public, finding this information out using the available NASA tools is a slow process, and understanding what you've discovered is difficult without good visualization.

Introducing the Prospector's Skymap, a tool for visualizing Earth-centric plots of asteroid trajectories over the next 20 years, in 3d. Included is ~500 asteroids that have low delta-v rendezvous. The blue part of the trajectory is "within range" of an average human mission duration of 6 months, which can be configured by setting the maximum lunar distance in the range box. See the online help.

In addition to visualization I've been doing some offline data processing. Probably the most interesting result is a list of targets that have low delta-v rendezvous requirements, close approach within 20 lunar distances, sorted by year, for the next 20 years. Here's the csv file.

* under 20 LD

Asteroid	Close approach	Distance (LD)	#days*
(2009 SH2)	2010 SEP 30	7.123335	37
(2005 UN)	2010 OCT 24	11.018314	26
(2006 JY26)	2010 NOV 04	14.304191	31
(2010 JW34)	2010 NOV 21	19.351126	16
(2008 KT)	2010 NOV 23	5.560636	61
(2009 BS5)	2011 JAN 11	3.397712	61
(2009 UK20)	2011 MAY 02	8.569228	30
(2009 BD)	2011 JUN 02	0.900437	127
(2007 RQ17)	2011 JUL 22	13.230543	56
(2007 DD)	2011 JUL 23	9.295763	44
(2009 TM8)	2011 OCT 17	1.101829	22
(2009 WN6)	2011 NOV 05	6.324271	24
(2008 UR)	2011 NOV 13	17.551555	19
(2008 EL68)	2012 JAN 05	8.296077	46
(2008 EJ85)	2012 MAR 06	9.229096	25
(2010 FR9)	2012 MAR 22	18.405986	8
(2001 CQ36)	2012 MAY 30	10.003372	28
(2009 BW2)	2012 AUG 09	13.121943	25
(2010 JK1)	2012 NOV 25	9.307960	28
(2008 ON10)	2013 AUG 16	19.019998	13
(2007 CN26)	2013 AUG 28	11.860884	21
(2008 PW4)	2013 AUG 30	13.848723	19
(2005 TG50)	2013 NOV 12	15.926447	38
(2001 AV43)	2013 NOV 18	2.889049	103
(2004 FJ31)	2014 APR 10	11.569571	18
(2007 HB15)	2014 APR 28	7.406142	28
(2010 KV7)	2014 AUG 15	17.871782	17
(2006 WZ184)	2014 NOV 09	19.820336	4
(2010 GH7)	2015 MAR 20	7.382686	35
(2006 HX30)	2015 MAY 16	11.011628	32
(2007 BB)	2016 JAN 16	11.164091	39
(1994 UG)	2016 MAR 25	17.275873	12
(2008 HU4)	2016 APR 16	4.882098	136
(2009 DL46)	2016 MAY 24	5.954658	26
(2005 OH3)	2016 AUG 04	6.467120	48
(2007 RU19)	2016 AUG 11	13.429743	22
(2004 KG17)	2017 MAY 16	10.747414	30
(2006 SR131)	2017 SEP 27	12.113018	15
(2001 WH49)	2017 OCT 26	15.114138	23
(2006 XY)	2017 DEC 20	6.146966	35
(2008 WM61)	2017 DEC 02	3.592903	38
(1991 VG)	2018 FEB 11	18.367953	47
(2010 AG3)	2018 MAR 04	15.753700	25
(1999 FN19)	2018 MAY 07	9.646226	28
(2008 HS3)	2019 MAY 10	14.449071	23
(2001 KW18)	2019 MAY 21	17.545783	18
(2006 QV89)	2019 SEP 21	14.496112	28
(2008 UD95)	2019 OCT 08	16.756188	26
(2008 EA9)	2019 NOV 23	11.242446	71
(2007 UN12)	2020 JUL 04	16.821816	37
(2009 OS5)	2020 JUL 14	17.843878	32
(2001 GP2)	2020 OCT 03	3.124592	67
(2008 TY9)	2020 OCT 10	17.516709	15
(2007 TA23)	2020 OCT 12	16.497889	21
(2008 GM2)	2020 OCT 25	15.820380	30
(2005 AZ28)	2020 NOV 10	13.804279	26
(1993 BX3)	2021 JAN 17	18.420554	19
(2004 RW2)	2021 SEP 05	15.734705	15
(1982 DB)	2021 DEC 11	10.235235	23
(2009 BF58)	2022 JAN 25	6.081125	23
(2008 JP24)	2022 JAN 26	19.229932	9
(2007 UY1)	2022 FEB 08	13.889908	19
(2009 FX4)	2022 AUG 05	9.989264	35
(2003 YS70)	2022 DEC 13	10.017109	38
(2004 XD51)	2022 DEC 27	11.596943	25
(2006 EW)	2023 FEB 12	14.574834	20
(2004 OW10)	2023 MAR 25	12.791391	24
(2009 QR)	2023 AUG 21	2.686016	33
(2001 QQ142)	2023 DEC 06	14.377189	19
(2005 FG)	2024 APR 07	15.856559	19
(2009 FK)	2024 MAY 21	17.909620	13
(1998 KY26)	2024 JUN 01	11.985906	27
(2005 ND63)	2024 JUL 14	14.224540	14
(2002 NV16)	2024 OCT 24	11.756611	58
(2006 HU50)	2025 MAY 02	9.260892	23
(2008 ST)	2025 MAY 20	14.253036	51
(2008 DG5)	2025 JUN 06	9.085841	25
(2008 CM74)	2025 JUN 25	4.864523	43
(1999 SF10)	2025 DEC 18	7.278969	64
(1999 AO10)	2026 FEB 13	10.433361	56
(2000 SZ162)	2026 OCT 16	14.385593	24
(2006 SF281)	2026 OCT 18	6.039328	42
(2009 SH1)	2026 SEP 17	10.783613	19
(2009 HC)	2027 APR 10	6.023004	80
(2008 VC)	2027 NOV 02	5.114356	33
(2004 AD)	2028 JAN 06	18.270946	9
(2005 ER95)	2028 MAR 23	13.025330	46
(2009 FQ32)	2028 MAR 31	3.803212	38
(2009 WC106)	2028 MAY 02	16.250076	21
(2000 SG344)	2028 MAY 07	7.636435	212
(2009 WR52)	2028 MAY 20	2.464651	31
(2006 RH120)	2028 AUG 08	11.213795	188
(2008 EY84)	2028 SEP 09	11.883114	31
(2007 DC)	2028 NOV 05	5.717175	50
(2006 SU49)	2029 JAN 28	3.187666	37
(2006 UQ216)	2029 FEB 19	13.495717	45
(2009 CV)	2029 MAR 03	8.612422	77
(2007 WA)	2029 MAY 13	6.036336	34
(2000 SL10)	2029 MAY 16	6.760240	21
(2010 NN)	2029 JUN 14	12.258461	21
(2009 DC12)	2029 JUL 06	18.680698	15
(2008 TN9)	2029 SEP 29	18.178757	10
(2006 HE2)	2029 SEP 30	2.029127	34
(2008 UA202)	2029 OCT 20	5.299326	60

From this data you can determine which target is most favorable in any given year. If you're after really low delta-v requirements, as well as short transit times, then the list gets smaller.

Asteroid	Close approach	Distance (LD)	#days*	delta-v
(2010 JW34)	2010 NOV 21	19.351126	16	4.839129
(2008 KT)	2010 NOV 23	5.560636	61	5.800001
(2009 BD)	2011 JUN 02	0.900437	127	4.793479
(2005 TG50)	2013 NOV 12	15.926447	38	6.153250
(2008 HU4)	2016 APR 16	4.882098	136	4.577387
(1991 VG)	2018 FEB 11	18.367953	47	5.238135
(2008 EA9)	2019 NOV 23	11.242446	71	5.392948
(2007 UN12)	2020 JUL 04	16.821816	37	6.080512
(2009 OS5)	2020 JUL 14	17.843878	32	5.764455
(2001 GP2)	2020 OCT 03	3.124592	67	5.595356
(2008 ST)	2025 MAY 20	14.253036	51	5.637181
(1999 AO10)	2026 FEB 13	10.433361	56	5.858708
(2005 ER95)	2028 MAR 23	13.025330	46	5.814350
(2000 SG344)	2028 MAY 07	7.636435	212	5.197308
(2006 RH120)	2028 AUG 08	11.213795	188	3.385696
(2006 UQ216)	2029 FEB 19	13.495717	45	6.081869
(2008 UA202)	2029 OCT 20	5.299326	60	5.953219

And the list of known near-Earth asteroids keeps growing.

Mission To Asteroid Using SpaceX Hardware - NASA's Target

2010-08-14T16:25:00.003+10:00

As a target of study, NASA has identified the asteroid 1999AO10 as the 2025 destination for human exploration. We've heard that NASA plans to build a giant heavy lift vehicle to make the trip, but is it really necessary?

I previously described a human asteroid mission, but I assumed the logical choice of asteroid with the lowest known delta-v (and included analysis for the second lowest too), but for some reason this isn't as interesting to NASA, so let's consider how one might do the trip to their preferred target, using existing SpaceX hardware.

The reference numbers are: Earth departure stage 3291m/s, and storable propellant 3939m/s of total delta-v. We could improve this by carefully measuring the boiloff of LOX in Falcon 9 upper stages and analyzing the required insulation to do the arrival rendezvous using non-storable propellants, but I don't really have that information handy, so I'll just go with the storables.

Like last time, we'll use the Dragon spacecraft as our crew vehicle. Unlike last time we'll actually have a look at the thrusters, it uses 18 Draco thrusters which are similar to the Aerojet 445 in performance with 309s of ISP. The Dragon is carried to orbit on a Falcon 9 with 3000kg of payload in the "trunk", 3000kg of payload pressurized (that includes the astronauts), and 1290kg of storable propellant, giving a dry mass of around 1710kg. To provide 4710kg (dry mass + pressurized payload) with a total of 3939m/s of delta-v requires a gross mass of 19544kg, which means the external tank will be 13544kg when filled.

The Earth departure stage will be the Falcon 9 upper stage, with the Merlin 1C vacuum performance of 342s ISP. The total initial mass in low Earth orbit is therefore 56710kg. Meaning 37166kg of that is LOX/RP-1. With a mixture ratio of 2.56, that means 10440kg of RP-1 and 26726kg of LOX. (btw, if we had a Raptor stage the IMLEO would be 46328kg, and presumably mass-to-LEO of each flight would be bigger, but the boil-off analysis would be completely different, as you'll see).

Ok, so we have all the numbers we need, now we just have to decide what order to launch it all in to reduce the total mission risk. Storable propellants are called that because they can sit without being used for long periods of time and be ready to go when needed. Also, they don't suffer from boil-off when stored on-orbit, or at least not so much as we need to care in this kind of analysis when compared to cryogenics like LOX. As such, I'm of the opinion that the best strategy is to launch the storable propellants in the external tank, and the RP-1, first.

This is a total of 23984kg and includes some of the mass for the tanks to contain the propellants. So we're looking at two Falcon-9 flights with a shortfall of 3084kg. If an initial parking orbit is chosen well, these first two flights can be spread out over as long a time period as desired, limited only by orbital decay.

We now need to deliver 26726kg of LOX, along with the remaining 3084kg of non-cryogenic propellants, for a total of 29810kg. These three Falcon-9 flights will deliver 1540kg of excess LOX which should account for boil-off if the flights are launched without delays. At 0.1% per day boiloff, the launch campaign must be complete in 50 days. But we have an ace up our sleeve.

The final flight of the launch campaign is the manned Dragon. It will be carrying the crew, with all their provisions, on-board propellant, some of which will be used for rendezvous and orbital assembly activities, and 3000kg of LOX in the trunk. Carrying cryogenics in the trunk may seem risky, but it has such an awesome payoff on cryogenic boil-off that it's worth it.

As described in the NASA concept, the mission departs the low Earth parking orbit, and arrives at the asteroid 3.5 months later. The astronauts stay on the rock for 2 weeks, then return to Earth a month later. The entire trip is 5 months. Radiation exposure is similar to a year long stay on the ISS, about half of an astronaut's lifetime limit.

Because of the suboptimal choice of destination, the new mission has five tanking flights at $56M each, and the manned Dragon flight which I estimate at $150M, for a grand total of $430M. This is about 100 times less than what I expect NASA will spend trying to do the same thing.

The Asteroid Menace

2010-08-11T17:48:00.005+10:00

Day one of the Exploration of Near Earth Objects Objectives Workshop saw the presentation of three key reasons to send humans to visit asteroids: science, mining and planetary protection. Of these, the last has has been shown to be an issue that attracts mainstream support, no doubt we have Bruce Willis to thank for this.

The workshop began with presentations of the robotic missions that have been flown to asteroids and comets. The recently returned sample return mission Hayabusa, taking pride of place. All the presenters had war stories of the operational difficulty of flying to these objects, and some expressed surprise that their missions succeeded at all. They also talked about the high cost of these missions in terms of remote sensing equipment and the lack of good ground truth information to calibrate these instruments.

Unsurprisingly then, they all support a human mission to an asteroid or a comet near Earth to more efficiently gain scientific results. However, when asked about planetary defense, the consensus opinion wasn't just that a human mission would be nice: it is absolutely necessary.

Here's some interesting audio from the workshop.

An asteroid is heading to Earth that will kill every one of us, someday. Hopefully we will discover it and track it for long enough to have 5 or 10 years prior notice. Now what? We'd love to send a robotic probe to get some idea of what the object looks like, what it is made of, how fast it is rotating, etc. Unfortunately, a robotic mission will take at least 5 years to go from concept to launch and it has a very low chance of success at even this precursor mission. Sending a robotic mission to deflect or otherwise mitigate the threat is simply unthinkable at this time.

That means we need to send humans, and it means we need to send them to meet the threat with no robotic precursor. The astronauts will do the scientific investigation to determine the composition of the object. This will most likely include planting seismic detectors, and launching one or more kinetic impactors into the surface. Relaying this data back to Earth, the astronauts would wait for ground control, probably with the support of the national laboratories, to decide on a mitigation plan. Obviously the plan will be limited by what the astronauts have with them, so they will need to carry an array of tools for the various types of threats that may be expected.

For example, the best strategy may be to install large motors which provide constant thrust for a period of years diverting the asteroid off course just enough to miss the Earth. Such a strategy would only be possible on objects where in-situ resource utilization could produce sufficient propellant. Another strategy may just be the placement of a station keeping spacecraft with a lot of mass, possibly removed from the surface of the object, to act as a "gravity tractor", again diverting the course away from Earth. More exotic strategies may include converting rotational energy into propulsive energy using long tethers or in the drastic use of nuclear bombs.

The workshop continues today and is being webcast. Ultimately, failure to send astronauts to visit near-Earth objects within the next few decades will be fatal to humanity, so tune in and participate.

Deep Fried Astronauts

2010-08-09T17:47:00.002+10:00

Back in 1967 the Bellcomm put together a study for the then Manned now Marshall Spaceflight Center. The mission was a one year human flyby of Venus. The study included some innovative stuff, like using the Earth departure stage tanks as a living module after venting any remaining fuel into space, but it also contains a fair bit of misinformation about radiation exposure, advocating that no attempt be made to shield against galactic cosmic radiation. This is to be expected.

What isn't expected is that this is still the general consensus today, even though a more recent computational study has provided some interesting numbers for various shielding materials.

Shield Material (5g/cm^2)	Annual radiation dose (mSv*)
Aluminum	542
Polyethylene	450
Iron	581

* Quality factor recommended in ICRP-60 is assumed.

This looks pretty good when the astronaut lifetime radiation limits are considered.

Astronaut age	Career effective dose limits (mSv, average life loss)
	Males	Females
25	520, 15.7	370, 15.9
30	620, 15.4	470, 15.7
35	720, 15.0	550, 15.3
40	800, 14.2	620, 14.7

Polyethylene shielding works better than aluminum which works better than iron because it has more carbon atoms. Adding shielding to the spacecraft and only sending crew of the appropriate age can drastically reduce the amount of life you take from astronauts on one-year long missions. Of course, most Mars missions designs are much longer duration than this and so more heavy radiation mitigation is needed.

Before discussing those options, let's think about how heavy this "light shielding" actually is. A Saturn S-IVB provides a heck of a lot of space compared to an ISS module, and has proven sufficient for a one year journey by SkyLab. It was 17.8m long by 6.6m diameter. With flat ends, this is a surface area of 4,374,982 cm^2, and at 5g/cm^2 the polyethylene shielding would weigh 21,874 kg.

On a trip to Mars one does not only have to consider the fuel required to burn in LEO to get to escape velocity, one must also consider the fuel required to do course corrections to get to and maintain Mars transit and perform Mars orbit injection. One way to reduce this fuel is to carry a large heat shield and do aerobraking. All this fuel is mass, typically with a lot of carbon in it, and so can also be used to shield the crew.

It seems reasonable at this point to wonder exactly how much radiation protection you and I get here on the surface of the Earth. The answer "enough" is sufficient so perhaps a better question is, how? Go outside and look up, what do you see? Air. How much? The answer is 1,030g/cm^2. As such, the 22t of shielding we added is providing just 0.49% as much protection.

If we want to provide sufficient radiation protection for long duration spaceflight, it seems obvious that we need to make the spacecraft smaller. Shielding just a smaller part of the spacecraft would be pointless as the crew is required to stay in there for the majority of the trip anyway.

Let's consider a 8m long cylinder of 4m diameter. Internally, it would be about 80 m^3 of pressurized volume. The surface area is 1,256,637.06 cm^2. Here's the masses required for various levels of radiation protection.

Radiation protection (vs sea level)	Mass (kg)
1%	12,943
5%	64,717
25%	323,584
50%	647,168
100%	1,294,336

As you can see, the life expediency of the crew can be improved by almost 3.5 times by reducing the surface area of the living volume by just under half. An interesting rule of thumb: 7% of Earth normal radiation shielding takes one year of lifespan off men for every year spent on the mission.

Making the spacecraft even more cramped and arranging the storable propellant and supplies as additional shielding would permit the creation of 5% of Earth normal radiation shielding, meaning the crew could go on the long multiyear excursions required to explore Mars, but no conceivable technology today can practically provide passive shielding for 100% radiation protection.

Throwing Stuff In Space

2010-08-08T12:38:00.002+10:00

In my last post about the Russian space program I said that cosmonauts regularly throw stuff in space so it will burn up and not result in permanent space junk. A reader asks whether you can actually do this.. Man, way to ask a hard question.

Orbital mechanics says "if a space vehicle comes within 120 to 160 km of the Earth's surface, atmospheric drag will bring it down in a few days, with final disintegration occurring at an altitude of about 80 km", and we can work out how much delta-v a cosmonaut has to impart to get the semi-major axis of the orbit of the debris below 160 km.

dVA = sqrt(GM*(2.0/rA - 1.0/((rA + rB) / 2.0))) - sqrt(GM/rA)

where rB = 160km + roE
where rA = 278km + roE to 460km + roE
where roE = 6378.1km
where GM = 6.67300 * 5.9742 * 10^24 * 10^-11

with the ISS at 278km the delta-v retrograde is 34.684365m/s or 77.5867148 mph, which is major league baseball.
with the ISS at 428km the delta-v retrograde is 77.243278m/s or 172.788292 mph, with is space cannon territory.

Ok, let's work out how long it will take to degrade from 250km as a throw to that altitude from the ISS is pretty easy most the time.

We need to know how big the thing we're throwing is, let's say 1m x 1m and 100kg, with a drag coefficient of 2.67.

a = 250km + roE = 6628100

darev = (-2 * pi * Cd * A * p * a^2) / m
darev = (-2 * pi * 2.67 * 1 * 2.62 * 10^-12 * 6628100^2) / 100
darev = -19.3094776

L ~ -H / darev
L ~ -58200 / -19.3094776
L ~ 3014.06393 orbits

P = sqrt(4 * pi^2 * a^3 / GM) = 5369.860522 seconds

L ~ 3014.06393 * 5369.860522 seconds
L ~ 187.32758 days

So the answer is: it's unlikely. It depends how high up the ISS is and how long you're willing to wait for the debris to fall below the 160km altitude. Just letting the part go without a throw will cause it to reenter eventually because no low-Earth orbit is stable, but if you want it to come down in just months you've gotta throw it, and note that you don't throw it "down", you throw it retrograde, and preferably at periapsis, but that's any point on a circular orbit.

Thanks for the question Ian.

A Disappointing End To The Russian Space Station Program

2010-08-07T17:57:00.005+10:00

Thankfully no-one really cares about the Russian space program, or, ya know, they don't speak English, I guess. Everyone has heard of Mir but name any prior station. Go on, name one. Ok, that's easy, but how many space stations did the Russians have before Mir? I'll get back to you on that.

So what was the point of all these stations? We all know the reason why the US has the ISS, and anyone who watched the Augustine committee proceedings last year heard about why the "international community" is demanding it be extended until 2020 and beyond. Scientific research or something right? The 2005 NASA Authorization Act designated the ISS as a national laboratory. Oh sorry, the American segment of the ISS, because obviously the US can't designate the Russian segment as a national laboratory of the US, but that's what it is right? Well, no.

The Russians do very little scientific research on the ISS. They have only "mini-racks" on the Poisk module, and finding out what exactly they do is harder than finding out all the "world class research" that the US apparently does on their side of the station - and that's saying something. So what, maybe the Russians just don't care about scientific research. Ahh, no. (I should stop finishing paragraphs like that).

Starting before their first station the Russians flew a series of Bion satellites which contained a whole heck of a lot of biomedical experiments - most of them a lot more ambitious than what is apparently done on the ISS these days. In fact, people groan at me when I say they didn't go far enough with their rat life-cycle experiments because no-one has ever done anything like it since 1979. However I hear the upcoming Nauka module to the ISS will have rat experiments, maybe they'll continue that research.. and that has me worried. Although mammalian reproduction experiments in space are important - stop giggling children, we're never going to colonize space if we can't have babies out there - that's not what the Russian human space program is about.

Their first station was Salyut 1, and by all accounts it was an unmitigated failure. The crew actually died on the way back to Earth and no-one ever returned to the station, it was deorbited after just 6 months. This immediately set the tone for the Russian space program, if people had to die to do work in space then it better be important work. So the next station, although called Salyut 2 was actually a military station under the secret Almaz program. Many consider this a distinction without a difference, after all, everything was secret in the Soviet Union. To those people I say: the Almaz stations were armed with freakin' cannons! They actually shot down test satellites with it.

Of course, Almaz was also an unmitigated failure. No-one made it to the first one. Salyut 3 had only one crew, and although Salyut 5 had three crews, one of those crews couldn't actually get into the station and had to turn around and go home. But hey, space cannons!

Whereas, the "civilian" Salyut program was significantly more impressive, it had to be, the world was watching. The last, Salyut 7, was visited by 10 crews including French and Indian cosmonauts, and did 13 spacewalks. The experienced gained from in-space operations was considered the primary payoff of the program. They demonstrated the multi-module principle that led to the seven module Mir, with the goal of a permanently human occupied station.

Then the international cooperation started. Of course, the 30 years of experience the Russians had paid for, with both Rubles and human blood, wasn't worth squat to the Americans. Even now, 12 years into the ISS program, I'm regularly told that the US shoulda gone it alone with Space Station Freedom. Oh, and then there's the complaints that Russia hasn't spent as much building the station, because dollars are such a great metric of productivity. In my opinion, the ISS would be scattered over the Australian outback (or Canada) by now if it wasn't for the Russians.

Let's take a modern example. Recently, two Russian cosmonauts did a spacewalk to install a new homing beacon and throw away an old camera - the standard boring maintenance that you do on a space station. Watching the spacewalk on NASA tv was enthralling - yes, I just said that, NASA tv was enthralling. The cosmonauts were crackin' jokes, and making fun of the bad comms with mission control, oh, and making decisions. They were sent out the airlock with nothing more than the broad goals and a rough schedule, the rest was up to them. (oh, and they didn't "create space junk" by throwing away that camera, cosmonauts actually know how to throw stuff in space to put it into a degrading orbit which will burn up.)

Just three days later an ammonia coolant pump broke on the American side of the ISS. My first reaction was to wonder if they were going to scramble the Shuttle to fix it, or downplay the problem until the Shuttle gets there in November. But no, they're going to send two of the expedition crew out to replace the broken pump. What a unique opportunity to compare the two programs.

Whereas cosmonauts are both involved in the planning and have operational decision making responsibility of spacewalks, astronauts are not. Two days after the failure, ground control decided to cancel already planned spacewalks to focus on planning the "repairs". Five days after the failure, the spacewalk to replace the pump was delayed, "to give planners more time to fine-tune the required procedures." Yesterday, eight days after the failure, the plan for the spacewalk was released, tune in to NASA tv to watch the spacewalk, oh sorry, spacewalks and see how many jokes and decisions the astronauts make on their own.

Space is boring because there are no humans in space, they're just robots in human form. Humans make jokes and decisions, they get frustrated, they argue their opinions and have ambitions. Human space programs do too. Saying you want to go to Mars some day is visionary, but actually doing it involves cutting humans off from ground support. It involves trusting them to make the right decisions. It means actually fixing broken coolant pumps, not just swapping them out and sending the order in to BoeLockMart for a new one.

To the Russian people I say: keep demanding humans in space doing important work to prepare humanity to go out into the solar system, leave the "science" and "spinoffs" and all the other justifications to the US.

Nuclear Rockets In The Atmosphere?

2010-08-06T10:33:00.005+10:00

In James Dewar's latest book he proposes the development of a new solid core highly enriched uranium rocket engine based on the B-4 core developed in the Rover/NERVA program, but unlike that program he recommends starting small, testing in a dedicated exhaust processing facility and building successive generations of engine to prove safety and gain operational experience.

The first engine to be put into operation would have 40,000lbf (800MW), an ISP of 1,000s and weigh 6,000lb. It would have a maximum burn time of 15 minutes. The gross mass for the stage would be 91,000lb with 45,000lb of LH2 fuel, and a 3,000lb cocoon to recover the engine, to deliver a 17,000lb payload to LEO*. The stage would be dropped from 50,000ft by a cargo plane (such as the C-5A), and solid rocket boosters would carry it to 100,000ft before the solid core engine engages. The deorbited engine in its cocoon would be recovered from a splashdown for processing, as the U-235 would only be ~1% spent in the short burn required for orbital insertion.

This is just the first operational vehicle, bigger payloads to justify the cost would follow - Dewar makes recommendations for other rocket engines in the book, but this is his pièce de résistance.

Obviously, there are a lot of political issues to overcome before this could ever be funded at a government level and, excluding Bond villains, it almost certainly would have to be a government program. But what are the technical arguments against this? What are the (non-nuclear-hysteria) safety arguments?

And, to counterbalance the risk, are there good arguments for such a program?

These are not rhetorical questions, I want your opinion.

* in metric: 177,929N (800MW), 2,722kg. Gross mass for the stage would be 41,277kg with 20,412kg of LH2 fuel, and a 1,361kg cocoon, to deliver a 7,711kg payload to LEO.

Scaled Composites' Dirty Little Secret

2010-08-05T11:57:00.004+10:00

The public is incredibly easy to fool. Way back in 2004, Mike Melvill made history by flying Burt Rutan's beautiful creation SpaceShipOne across the unofficial border to space, twice, and later that year Brian Binnie did it again, winning the Ansari X-Prize and raising the hopes of all that private access to space had finally arrived. But how did they do it?

There is no question that Burt Rutan is a natural genius at aircraft design. His true innovation on SpaceShipOne was the shuttlecock styled effortless reentry system, and in particular, the ease of replacing these two large booms after a few flights to mitigate wear. SpaceShipOne/Two is a glider, and just like the Space Shuttle the wings are "only" used on the way down. There are wings used on the way up, of course, they are on WhiteKnightOne/Two, but once separated from the carrier aircraft the only lift is generated from the rocket.

As smart as Burt Rutan is, he's not a rocket guy. For SpaceShipOne he turned to Tim Pickens, a gifted rocket experimenter who became Scaled Composites' Propulsion Lead Engineer in 2002. It didn't last long, he was only there for a year, but in that time he gave them a motor. Think about that for a minute - it's truly remarkable. Because of that incredible pace the motor design was as simple as possible but no simpler, as they say. Being a hybrid, it shakes like a solid, along with half the reusability of a liquid.. and for some reason it can't restart and had half the performance of both. But it did the job.

Even before winning the prize, Scaled Composites signed a deal with Richard Branson to supply Virgin Galactic with a design for a new set of vehicles and form The Spaceship Company to put them into production. I'm not sure anyone thought it would take as long as it has, but Rutan set to work and delivered the scaled up vehicle designs with the creative names of WhiteKnightTwo and SpaceShipTwo.

Unfortunately, those designs also included details for RocketMotorTwo, which Scaled Composites decided to do in-house this time. Three years passed. In 2007 there was an accident which killed three and injured three more. Although the investigation cleared the company of any wrong doing, it was apparent that they were in a hole that they weren't climbing out of quickly enough.

In mid-2008 WhiteKnightTwo was unveiled. The media ate it up, but some of the statements made by Virgin Galactic's Will Whitehorn to promote the utility of the vehicle were a bit concerning. Everyone wanted to know: where's SpaceShipTwo? And the response seemed to be "we don't need it."

Late last year SpaceShipTwo was unveiled and Virgin Galactic had a big party. Since then, there has been captive carry tests and we're told there may be drop tests by the end of the year. It's all getting very exciting!

Oh I'm sorry, I was talking about the rocket wasn't I? I guess I got distracted by all the shiny white aircraft that I forgot all about it. Well, it seems Virgin Galactic have too.

Sometime between the 2007 accident and today Scaled Composites figured out that they're an aircraft company, not a rocket company, and decided to call in the Sierra Nevada Corporation to get back on track. Since then they've done hot fire tests which, of course, have been complete successes. Oh, they're using ablative nozzles too? Eww.

I've asked a lot of rocket professionals about these scraps of information and, in private, they've all told me the same thing. In public, "how would Jeff Greason say this?" is the what-would-Jesus-do of the space community, and this is how he said it:

In a sane world, a company that has a vehicle without an engine would purchase one from a company like XCOR, which specializes in engines.

So why can't Scaled Composites just buy the best rocket engines in the world (and yes, XCOR's engines really are that good). It would seem to be the rational decision. Apparently, the answer is simple: Rutan sold Branson a hybrid, so he has to deliver a hybrid. It doesn't matter how much hard won experience tells him that hybrids are not safer than liquids (or solids!). It doesn't matter that there's now acceptable engines that you can buy off-the-shelf that just weren't available 10 years ago when Rutan made his decision to go it alone. To change the deal now would loose face and more than likely have contractual implications.

And that's Scaled Composites' dirty little secret.

Coding Orbital Mechanics

2010-07-28T17:47:00.000+10:00

I forget what inspired me, probably discussions about propellant depots, but after an hour of two playing around in the great spaceflight simulator Orbiter I decided to give the old orbital mechanics another go.

I've written dynamic physics simulators before which have really nice accuracy and can handle the big numbers required for orbital simulations, including three body problems, but I never managed to tackle the classical orbital mechanics - too much Greek terminology I guess - until today.

I set myself a somewhat difficult task:

Given a position vector r and a velocity vector v, somewhere above a reference (say, a planetary body) calculate all the required classical orbital elements:

a - semi-major axis
e - eccentricity
i - inclination
l - longitude of the ascending node
w - argument of periapsis
t - true anomaly

There's others, but they can be derived from these. You'll also note I haven't used any Greek letters that my keyboard doesn't have. I can also do the reverse: convert classical orbital elements back into state vector elements.

So what is this good for? The true anomaly tells us where the object is in the orbit relative to the lowest point in the orbit (the periapsis) and has an interesting operation: you can add (or subtract) time to the orbit to get a new position. To do this, one calculates the mean anomaly and adds to it a multiple of the mean motion. From the mean anomaly you can calculate the eccentric anomaly, but this has to be done numerically. Then the eccentric anomaly can be converted into a true anomaly and we're done - but don't forget to correct for range and remember what quadrant of the orbit you're in.

    void step(double time)
    {
        double M = meanAnomaly();
        M += meanMotion() * time;
        while (M < -2*M_PI)
            M = M + 2*M_PI;
        if (M < 0)
            M = 2*M_PI + M;
        while (M > 2*M_PI)
            M = M - 2*M_PI;
        double E = calcEccentricAnomaly(M);
        calcTrueAnomaly(E);
    }

This means we can add any duration of time, with any desired accuracy, and expect to get an accurate result. In comparison, numerical simulations of newton's laws often give more inaccurate results the longer you run them. On the other hand, doing accurate orbital perturbation and rocket burn simulation with classical orbital elements is very difficult, and accurate three body solutions are still considered unsolved problems. As such, having the ability to accurately convert from these two very different systems gives you the best of both worlds.

Here is the code, in all it's C++ glory. Feel free to use it for whatever you like. In writing it I found the descriptions on orbital state vectors from Wikipedia particularly helpful, along with appendix C of the Orbiter manual and this Numerit application note.

How about that! I combined the two topics of this blog in a single post.

Dr Paul Spudis Responds - Sorta

2010-07-24T19:11:00.012+10:00

I thank Dr Paul Spudis for responding. His post isn't addressed to me but it certainly appears to be directed at me.

Clearly if we don’t go to the Moon with people or machines, there is no way to use the abundant water, metals, and other lunar surface materials to create new capabilities in space. Supporters of the new path suggest instead that we can obtain all the materials we want from near-Earth asteroids

.. in my dreams! Us asteroid mining advocates are a minority who have been swept aside in this debate. Asteroids are a "stepping stone" to Mars, not a destination. As Clark puts it:

As pointed out many times here, the main impetus for the Flexible Path option was simply to have useful and interesting in-space missions underway while landing and surface systems for Moon and/or Mars were in development.

Spudis also makes good points about the difficulty of extracting resources from asteroids. This is often cited as justification for human missions. What he doesn't address is the question of gravity requirements, or radiation protection, for humans living long term on the Moon, and how they compare to what is feasible on (or inside) an asteroid. This, to me, suggests that Spudis continues to look at space as the future mines rather than the future homes of humanity (which is admittedly better than the pure "exploration and science" mindset of other people).

I do note however that Spudis has finally adopted teleoperated robots on the Moon as his own idea.

In terms of closeness, it takes 3 seconds for a radio signal traveling at the speed of light to go the Moon and back. This makes the remote, telepresence operation of lunar robots from Earth feasible.

Maybe eventually he'll stop being a human spaceflight advocate for a while and try to get some influence over the currently exploration-and-science directed robotic program for the Moon..

I look forward to that day.

Book Of The Week: Kim Stanley Robinson's Mars Trilogy

2010-07-23T22:21:00.001+10:00

The Book Of The Week this week is Kim Stanley Robinson's "Red Mars", "Green Mars", "Blue Mars". This is often referred to as the Mars Trilogy, but none of these books are about Mars. There's plenty of awesome scientifically accurate detail in these books on Mars geology, the moons of Mars, Mars colonization, Mars terraforming, and even some interesting speculation about Mars native life and building a space elevator on Mars. The books are certainly set on Mars but that's as far as it goes. In my opinion, these books are as much about Mars as Hamlet is about Denmark.

These books are about politics, the real kind, and what happens when it devolves into war. The books start with group dynamics, petty infighting, the formation of camps and the inevitable fracturing of community. The lines are: those who want to terraform Mars and those who want to keep Mars red. But the battle lines don't really matter, what was shocking was how quickly those two viewpoints became irreconcilable, and dominate the entire debate - by the time the shooting starts there are no third options, you're either a green or a red.

To me, these books are Kim Stanley Robinson's cautionary tale to the space advocacy community. We are already fractured. Moon vs Mars with asteroids, orbital colonies, space solar power, spaceplanes vs VTVL, SSTOs, and all the rest. We snip and we snarl, run our separate conferences and roll out our separate experts to influence the politicians. With all the aggressive personalities that we've acquired, and even elevated to leadership positions... thankfully we're all so friendly, for now.

Misrepresenting The Gap

2010-07-23T08:06:00.001+10:00

Ever get that feeling you're shouting into the void? Rand Simberg, someone who's opinion on space I truly value, has written an article on The Gap, and taken the well trod path of how bad it is to be reliant on the damn Ruskies.

With the coming retirement of the Space Shuttle, the most immediate issue in human spaceflight is how to get U.S. crews to the International Space Station.

When the decision was made in 2004 to retire the shuttle, the plan was to have a small "gap" starting this year, during which the Russians would provide this service, as they did for the two-and-a-half-year period after Columbia was lost.

But if lawmakers in the House have their way, we could be buying rides from Russia to the space station for the foreseeable future.

Argh. Rand, you know better, so I'm just going to have to assume you're playing down to the saps who read AOL News (and I imagine they are saps, cause who reads that?). As you know, the Soyuz has been used to carry American astronauts to the ISS since late 2000. Simply, if you're going to the station on the Soyuz you're there for the long haul, but if you go up on the Shuttle you're there for a visit, due to the Shuttle's on-orbit endurance and the logistics of lifeboats.

The comparison to Columbia is all wrong.. the "gap" there was the Shuttle not being available to continue building the station, or deliver supplies. It had nothing to do with getting US crews to the ISS, as the Soyuz has always been the way expedition crew members get to the ISS. That's the way the ISS is structured: the Shuttle builds the station, the Soyuz delivers the crews.

I fear that articles like this one do nothing but inflame misguided protectionist policies that threaten the partnership of the ISS. If the US decides to back out of the agreement to use the Soyuz, which has been the deal since 1992 (yes, 1992) then international cooperation will be severely strained, perhaps to breaking, and that would be an exceptionally stupid way of pushing American exceptionalism.

[update]

Rand is arguing with me over at his blog, and saying a lot that he didn't say in the article. He's yet to address the second paragraph I quoted, which I think is the most indicative that he doesn't know better. The Russians did not just "provide the service" of getting crews to the ISS during the two-and-a-half-year period after Columbia was lost.. they've been providing that service since 2000.. that's what they do, it's their major contribution to the operations of the ISS. Unfortunately, I think a lot of Americans think the same way - that Soyuz takes cosmonauts to the station and Shuttle takes astronauts to the station - that isn't the case, it never has been the case, and other than backstabbing protectionist politics, I can't see why anyone would want it to be the case.

Hating On Propellant Depots

2010-07-22T09:56:00.003+10:00

Dan Adamo is a retired flight dynamics officer for the Shuttle program and does space mission trajectory, design and operations in his sleep. I recently saw him put together a design reference mission for a human mission to the moons of Mars, for fun, using only well understood technology. Back in February he did a Space Show Classroom where he discussed many topics and once again demonstrated his effortless grasp of orbital dynamics.

A listener asked about propellant depots and Adamo answered with what I think is the most articulate objection to the concept of low earth orbit propellant depots. He went on to talk more favorably about propellant depots at Lagrangian points and on the surface of destinations such as the Moon and Mars, but I think his objections are more interesting.

Starting from the ground up, here's where I have problems with propellant depots, in low Earth orbit.

Once you establish the depot, it can be empty for all I care at this point, but once you establish it's orbit you have an orbit who's plane is at the mercy of perturbation, namely the earth's oblateness, which is going to cause it to regress westward, like we talked about - a few degrees a day depending on the inclination. So there's only certain times that you can leave that orbit plane for the Moon, and there's only certain times where you can leave it for, let's say, Mars, or some other intermediate destination like a near-Earth object, an asteroid.

I can almost guarantee you, particularly with near-Earth asteroids, that you can't pick one orbit plane, and have it work at-all frequently for the asteroid. The inclination will probably be wrong and let alone the other angle that orients the plane which is called the right ascension of the ascending node.

So you're at the mercy of this initial launch that puts the propellant depot on-orbit. You cannot pick when you want to leave like you can from a launch site that is rotating, ya know, with the Earth - on the ground, there's basically a launch window every day to whatever interplanetary objective you have and you're only going to spend just part of an Earth parking orbit before you depart low Earth orbit entirely, and you can pick what the orbital plane is - and make it the optimal for your mission objective.

Dallas Bienhoff from Boeing was on the show in May to discuss propellant depots and addressed a few of the concerns but, in my opinion, not the primary one.

He explained that a propellant depot in LEO would need to reboost itself and station keep, and seeing as it has an abundance of propellant (and boiloff of around 0.1% of hydrogen per day) that should be manageable, so that answers "at the mercy of perturbation" objection.

Bienhoff also offered numbers for out-of-plane penalties of 10% of delta-v, which he considered an acceptable tradeoff for the capability that a propellant depot infrastructure provides, and suggested this could be mitigated by choosing an initial plane which has the most demand from customers, and/or having multiple depots in LEO. Adamo actually said something similar earlier in the Show Classroom episode in response to a question of whether or not launching a Moon mission from the ISS was practical - which is certainly not an optimal orbit for lunar missions - he said it was, if there's a good reason to accept that penalty.

Adamo's primary objection remains, and I'll paraphrase it as: there are less launch window opportunities from an arbitrary low Earth orbit than there are from an arbitrary launch site on the surface of the Earth. Is this, like the 10% penalty of out-of-plane maneuvers, just another trade and something we have to live with? What are the actual numbers?

If anyone knows the answers to these questions, please leave a comment or email me direct.

[update]

I asked Dallas Bienhoff at New Space 2010 and his answer was, and I paraphrase: live with it.

I've gotten a much more detailed answer from Henry Spencer and his answer was, and I paraphrase: live with it, or spend more fuel, you've got a lot of it.

I think I prefer the second part of Henry's answer the best, by doing a burn to put yourself into an appropriate LEO orbit you can leave whenever you want, it just costs fuel but considering you're at a fuel depot, which is there for more than just your one mission, that seems reasonable.

I've asked Dan Adamo for comment, we'll see what he says.

My Reason For Human Lunar Return

2010-07-21T17:32:00.001+10:00

Why go back to the Moon?

I've asked that question a lot, and I've gotten a variety of answers.

There's a lot of nice resources on the Moon and the energy requirements to lift them from the Moon is a lot less than required to lift them from the Earth. There's water, which can be used for propellant, and there's metals, both in the lunar regolith and in more significant deposits from asteroid impacts.. but I disagree that we need humans to retrieve those resources.

The Apollo program only scratched the surface (literally) on lunar science. There's a whole lot of mysteries that lunar geologists don't have good answers for: nonmare domes, rilles, potentially active volcanic vents, the entire far side, and permanently shadowed craters.. but I again disagree that we need humans to do that science, and if NASA was at all serious about it they would have sent at least one rover to the Moon ever.

I have advocated the viewpoint that what should motivate human spaceflight is preparation for living in space. As Jeff Greason said:

You don't learn to live on other planets with robots. Space holds the future homes for humanity - we're going to live there some day if we are going to be a long term surviving civilization.

And by "live there" he means the kind of life we have here on Earth. To me, that means families.

So do I think humans will ever live on the Moon? No, not really. I agree with Dr Jim Logan that most likely there isn't sufficient gravity for humans to safely reproduce on the Moon.. but we don't know this, and he would be the first to tell you that.

Jeffrey Alberts of Indiana University has submitted a white paper to the upcoming Decadal Survey on Biological and Physical Sciences in Space, recommending NASA "reinstate its commitment to
studying mammalian development in space and in altered gravitational environments", including, "the role of gravity at all stages of the life cycle". He is advocating a variable-gravity centrifuge in LEO, as NASA has been directed to do in the NASA Authorization Bill For 2010.

That's all well and good, and it's certainly the cheapest and most efficient way to do it, right now, but should this module be canceled, like the Japanese module was, we will still need answers to this question. Simply, there is no point developing the technology to land on Mars if we can't eventually live there. We'll need to look at other destinations, such as Venus or asteroids.

Whether we have an answer to this question or not, the most reasonable interpretation of the Flexible Path calls for a human lunar return, after flights to interplanetary space, such as asteroids or the moons of Mars, and before a human mission to the surface of Mars itself. Some significant stay on the Moon is a likely goal, especially since we will have solutions to the long duration radiation exposure problem by then.

During that stay, a significant biomedical human factors study should be made, and most likely will be. Actual attempts at studying "all stages of the life cycle", although I expect would be fun if done with humans, will probably have to be done with other mammals. But without the human baseline of physiological reaction to long term exposure of lunar gravity, that data may be useless.

"Access To Space"

2010-07-21T10:36:00.002+10:00

Andre Bormanis has an article over at The Space Review which includes this nugget:

The US frequently partners with other countries and international organizations on space missions, primarily in the field of robotic exploration. Partnering in the development of manned systems has been resisted because of a belief, held deeply by many in government and among the public, that the US needs to have independent human access to space to maintain its status as a world power. If the Russians and Chinese can send people into orbit, so the reasoning goes, the US must as well, or risk being perceived as a declining power on the world stage.

Oh, is that what "access to space" means?

Well, as someone who is outside the US, I feel I can safely say: no-one cares. Yes, "soft power" exists, but no-one knows the names of astronauts anymore - they're just government employees who go up to an incomprehensible space station to pretend they're doing Important Work that has no real world implications.

Think about it, Russia has been consistently launching humans into space since the 60s with no gaps in their program, does anyone actually think of Russia as somehow being "powerful" because of this? No, we all think of Russia as a "declining power" because they suck at trade and foreign affairs and can't control their criminal population.

There is no sensible argument that can turn human spaceflight into a national security issue. No-one is going to invade the US because a spaceflight gap makes them look weak. ICBM technology is not driven by human spaceflight and it's arguable whether it ever was - and it's getting harder and harder to make any argument that nuclear armageddon is relevant to US national security in any case.

The closest thing to a logical argument ever presented for why human spaceflight is relevant to national security is that it inspires kids to go to college and do engineering which is of some value to the DoD (or something like that). This argument has been dismantled plenty of times. Penn and Teller even had a go, showing that kids really don't care, even when the entire day's activities involves crawling around inside a Space Shuttle simulator.

There's much better ways to inspire kids to enroll in engineering classes (and it should be obvious that by "kids" don't mean 10 year olds), like actually paying engineers more, describing how its a rewarding career (really, not sugarcoated NASA nonsense), and just showcasing how rich you can get if you're actually good at it and have some entrepreneurial drive.

CCDev Is Dead

2010-07-20T12:10:00.007+10:00

Ok, I don't usually write these sorts of things, but I think this is so incredibly terrible news that I feel the need to vent. The NASA Authorization Act of 2010 kills the commercial crew development program, while simultaneously killing any chance of funding SpaceX's COTS-D option. It contains these lies:

Sec. 241. Affirmation of Policy

Reaffirms the policy of making use of United States commercially provided International Space Station crew transport and crew rescue services; limiting the use of the government system to non-ISS missions once commercial crew transport and crew rescue services meeting safety requirements become operational; and facilitating the transfer of NASA-developed technologies to United States commercial orbital human space transportation companies.

All politicians lie, it's what they do, but it would be good if they could at least be consistent in the same document. What follows in Sec 242 is a long list of restrictions to make it completely impractical to do commercial crew, including this:

Directs the Administrator not to proceed with a procurement award for a commercial ISS crew transport system service if the provider’s crew transportation system has a predicted level of safety that is less than that predicted for the restructured exploration program’s crew transportation system.

In other words, it's ESAS all over again.. my paper rocket beats your flying vehicle because The Wiz said so.

But that's all just the flowery rhetoric, what matters is the numbers:

Sec. 101. Fiscal Year 2011

$14,000,000 is for the commercial cargo COTS demonstration program
$50,000,000 is for commercial crew transportation-related activities

Sec. 102. Fiscal Year 2012

$50,000,000 is for commercial crew transportation-related activities

Sec. 103. Fiscal Year 2013

$50,000,000 is for commercial crew transportation-related activities

Sec. 104. Fiscal Year 2014

$50,000,000 is for commercial crew transportation-related activities

Sec. 105. Fiscal Year 2015

$50,000,000 is for commercial crew transportation-related activities

Yes, those are in millions. $50M won't even buy you a test flight. $14M is close out money for COTS. Presumably the money for Cargo Resupply Services will come out of the ISS budget, but that isn't actually specified in the bill.. so for all we know it's the intention to kill commercial cargo too. [Clark Lindsey points out to me that the press release doesn't match the bill: "it provides more than $4.9 billion in funding for commercial crew- and commercial cargo-related initiatives".]

This bill still has to go through appropriations, which is where these numbers will actually be decided, and then it will be sent to the White House to be rubber stamped. The next time we see these numbers they will be law and we'll be stuck with them.

So far the White House is still saying they support the senate bill, but maybe their idea of "compromise" is trading the CCDev program (and keeping the Space Technology program) for the Nelson Rocket.

What Is The Gap?

2010-07-20T11:14:00.000+10:00

I don't even know anymore. Buzz Aldrin has written another article, this time over at the Huffington Post.

A number of my former colleagues, and other critics, have expressed concerns about the plan, and in particular, they express grave reservations about 'the Gap' -- the end of the Space Shuttle Program, and the inability for the US to provide human access to space -- save for limited flight opportunities and capabilities with our Russian partners, pending the maturing of the commercial space transportation capabilities, or other future systems to meet these needs.

So it's about "human access to space". Ok, to do what? Why do you want human access to space? What's the point of it? Unless you address that question you can't seriously talk about what kind of access to space you need. Will suborbital access do? No? Ok, how about one orbit? No? Ok, how about 2 days? No? How about 2 weeks, the endurance of the shuttle? No? Oh, permanent access to space? Like at some sort of space station? Wow, how ya gunna get there? Oh, that's right, you need the Soyuz to do that. Sigh.

I would also continue with the President's current plan to take advantage of the investment that we have already made in the Orion capsule, and use this capability as a lifeboat, or Crew Return Vehicle (CRV), for ISS, so we can fully man space station and exploit its magnificent capabilities.

Why? If it is cheaper to just buy more Soyuz lifeboats, why wouldn't you do that and free NASA to work on going beyond Earth orbit? How come using the Soyuz has been acceptable since 1992 (yes 1992) but all of a sudden the US needs a domestic lifeboat. What kind of partnership is it if the US is looking for ways to cut Russia out of the game?

I have proposed extending, or commercializing, the space shuttle system, which would preserve the opportunity for reduced manifest (one or two flights per year) support of the International Space Station, while also preserving the capability to develop a shuttle derived heavy lift launch vehicle to meet our future space exploration needs, and as importantly, maintain the critical technical workforce that supports our nations space transportation capabilities. A capability that we are in grave danger of losing in the few months ahead...

Jobs! You're gunna lose your jobs! Look at me, I care about your parochial interests! How does extending, or commercializing (oh, it is commercialized, as much as anyone is interested in doing) the Space Shuttle going to provide "human access to space"? Flying up on the Shuttle is necessarily a two week visit to space. You can't stay up there, because you don't have a lifeboat, and if you're going to buy them from Russia then you might as well launch humans on them. As for one or two flights per year, that is exactly the flight rate that the Columbia Accident Investigation Board said was too little to be safe..

Unlike Buzz Aldrin, there are some people who really think of The Gap as the lack of a new program to transition the workforce to. I think these people are more honest and, make more sense, than people who bang on about "being reliant on the Ruskies". They care about the layoffs and they want to see jobs preserved. As such, the recent "compromise" bill really is addressing The Gap. It extends the Shuttle just enough to keep jobs around for another financial year, or two, and it offers a new program where contractors can start to be transferred to (remember, no civil servants have been laid off).

The question is: do you want a jobs program or a space program?

You can't have both.

A Likely Scenario

2010-07-19T12:19:00.000+10:00

I was recently asked, "if a killer asteroid was approaching Earth, how much would they actually tell us?" This is my response.

They'd tell you numbers which you wouldn't understand. Then the pundits would turn those numbers into something they can scare you with, probably overblowing the threat while they do so, and Concerned Citizens would go to their Congressmen demanding answers. NASA would provide those answers.. in a completely unintelligible way, and someone would interpret those answers as dismissing the threat. Then there'd be a big argument over whether it's a threat or isn't it.

Eventually one of the egg heads with a wife will get a lecture about talking like a normal person once in a while and a press statement would be released saying exactly how likely and excessive the threat is (after it went through a few committees to ensure it was easy enough to understand, and defend). By this time the media will be completely bored with the story and the press release will be ignored by everyone, except for the next committee which is tasked with finding a solution.

Having found the solution the funding will not be forthcoming as the whole thing has already been written off as a hoax. A few years of fighting for funding and being rebuffed later, the media will pick up on the story again.. perhaps after the threat has been renamed. This time a-solution-the-authorities-have-been-ignoring will be available and someone-better-lose-his-job-over-this.

Of course, the solution that came out of that committee was for a situation that hasn't been true for years now, so we need a new committee.. this time with the President's appointment. They'll listen to a dozen different proposals, some of which have already been discarded as worthless, and choose the one that has the best political chance of being enacted quickly.

Eventually it'll get funding but the project will stall after 2 years of development, but thankfully some of the runner up concepts also got a trickle of funding. There will be a political fight to fund the more successful project over the stalled project, but that will fail, instead more money will be directed towards the hopeless project, until finally the egos on both sides subside and come up with some "compromise" solution that will half work, averting the complete extinction of human kind but still killing a few million people in a far-off-land.

Everyone will swear that next-time-we'll-be-ready but not actually do anything to ensure that's the case.. a few years later researchers will complain that their funding for early warning systems is being cut, and the general public will not care because, hey, it didn't turn out to be as big a deal as they said it was going to be anyway.

How Near Are The Near-Earth Asteroids?

2010-07-18T18:13:00.000+10:00

Back in 1978, following three successful free flights of Space Shuttle Enterprise the year before and the first lift-off of Space Shuttle Columbia only 3 years away, planetary scientist Gene Shoemaker and astronomer Eleanor Helin collaborated on a paper which presented the then shocking conclusion that some near-earth asteroids required less delta-v to reach than Mars. The near-term availability of the Space Shuttle was key, as the high flight-rate it promised meant a manned mission to an asteroid could be staged in low Earth orbit for as little as 23 flights. At the time, it wasn't unreasonable to suggest that within a few years that would be as little as 6 months of staging, and the vehicle would be reusable!

Of course, the Shuttle's flight rate never got that high, and today's mission designs to Mars are measured in International Space Station masses to remind us of how long it takes to amass payload in orbit.

This paper, however, remains important for the math it contains. Almost as an aside, Shoemaker derives a formula that accurately estimates the delta-v requirement to leave LEO and rendezvous with an Earth-orbit crossing asteroid. He also shows that typical the delta-v requirement for return from one of these asteroids is less than 1km/s. Towards the end of the paper, using data from Helin, he presents this table:

At the time 8.7km/s was something to get excited about, but what is often misunderstood about this table is that Shoemaker is not saying that this is the minimum delta-v required to rendezvous with Anteros - this table is describing the delta-v required to make the fastest transit to Anteros.

Transit time is important for a manned mission as radiation exposure to the crew cannot be excessive, and the mass of consumables needs to be minimized. However, for robotic mining missions, this table is worse than useless. What is needed is the data calculated at the start of the paper for these targets, and presented in this horrible graphic that no-one seems to understand how to read.

The figure is ugly because it's trying to serve two masters: listing some reference delta-v values, like Mars and some main-belt asteroids, and demonstrating that Shoemakers "figure of merit" technique works for a number near-earth asteroids. The other figures in the paper suffer from the same problem.

So what is the delta-v required to reach Anteros, which Shoemaker identifies as easier to reach than Mars "by a significant margin"? It's 5.391km/s. That was absurd when it was first said. That's about the same as going to a moon of Mars, and most people at the time knew the asteroids were beyond the orbit of Mars. When you considered round-trip, or simple flyby delta-v requirements, it got even more shocking.

What was unbelievable then, is commonplace now. It seems obvious in retrospect that near-Earth asteroids would be easier to reach than Mars.. after all, they're closer. In 1982 an asteroid was discovered and called (4660) Nereus. It has a delta-v (4.979km/s) that is about as easy to reach as lunar orbit (~4.8km/s). That really doesn't make sense to a lot of people. How can something that isn't captured by the Earth be as reachable as something that is? In 1989 it got even better, an asteroid that only requires 4.887km/s of delta-v to rendezvous with was found. It happened again in 1991 (3.998km/s) and again in 2006 (3.813km/s). And there's lots more.

The "free return trajectory" used by Apollo 8 to go around the Moon took more delta-v than that last one. So how low can we go? In figure 4 Shoemaker has scrawled the words minimum "expectable" F by which he means figure of merit.

The arrow seems to be pointing at a figure of merit which we can read as about 5km/s. This is clearly wrong both because Anteros appears on this chart future to the right and asteroids have already been discovered which require less delta-v. So who knows.. but look at what is written to the left. Surely, the required amount of delta-v to rendezvous with an asteroid has to be more than the escape velocity of the Earth, right? From LEO, that is ~3.2km/s.

We know this.. but I wonder if we know it the same way everyone knew the asteroids were all in the asteroid belt, back in the 70s.

Book Of The Week: Peter F. Hamilton's "Fallen Dragon"

2010-07-16T19:34:00.001+10:00

The Book Of The Week this week is Peter F. Hamilton's "Fallen Dragon". Although there's some similarities to military tales like Starship Troopers, the book is primarily a commentary on the ever encroaching power of multi-national corporations on our society and the individualist to community to national government struggles to live with it, along with some transhumanist alternatives.

Corporations in the future described by the book have taken over space colonization and found a somewhat inelegant solution to the problem of how to turn a profit: armed robbery. Of course, legally they're on sturdy ground - euphemistically referring to the practice as "asset realization" - but it's nothing more than tax extraction through force and so serves as a neat covert commentary on the origins of government power.

Hamilton's gift is his efficiency of description, and with space technology he manages to simultaneously summarize the great concepts for the lay-audience while adopting it to the setting of the book; for example, he describes O'Neill Colonies while explaining why future technologies have made the crop growing modules unnecessary.

This is one of the rare Peter F. Hamilton books that is not part of a series, so if you've never read one of his books, this is most likely the best place to start.

Buy it on Amazon

The Future Mines Of Humanity

2010-07-14T12:19:00.003+10:00

Dr Phil Harris is a Moon First space advocate and a published and acclaimed author. In his book Space Enterprise: Living and Working Offworld in the 21st Century, he goes into exquisite detail of the challenges and the bounties of industrializing the lunar surface.

In early January of this year Harris authored a special White House strategy paper [redistributed with permission] which recommended a pushing forward on the Vision For Space Exploration, or at least the Moon focused vision that came out of it. He makes it very clear that the reason to go back to the Moon is to get resources and reduce the national debt.

Now is the time to enlighten our nation's citizens of the vast resources to be tapped on the Moon. We could not only mine the lunar surface for valuable minerals and gems, but we could use its water and regolith to support lunar industrialization and settlement!

Those last two words are the only mention of settlement in the entire paper - so this is an economic argument and I feel the need to express my skepticism that such an economic argument can be seriously made at this time. Currently, the cheapest downmass from LEO costs $28,330 per kg. Although the price from the lunar surface would be much much higher than that, this is primarily due to a lack of in-space infrastructure. It's conceivable that strategically placed propellant depots with resupply from ISRU on the lunar surface could drastically reduce costs to a level feasible for lunar resource retrieval. More exotic cis-lunar infrastructure, such as Lunavators, could reduce those costs even more.

Harris also makes the argument that the Moon is the perfect place for all humanity's polluting industry, including power generation. This is an argument the Green movement could get behind: exporting the nasty side-effects of technological civilization to the Moon would leave the Earth to recover into a pristine reserve, without reducing the quality of life of the human population.

This argument is sound and reasonable. In response to the question: why go back to the Moon? Harris has a clear answer: industry and the wealth that flows from it (and settlement). In my words, the Moon is the future mine, and industrial park, of humanity.

Why Humans?

If you look at mining practices on Earth, you will see it is becoming more automated, as is all industry. In a sense, Rio Tinto and other mining companies are doing Moon-analog training in central Australia.

"It sounds crazy but quite a few of the problems in space and in remote mining can be similar," said Gipps, from the Commonwealth Scientific and Industrial Research Organisation (CSIRO). "You don't necessarily want to have people there... so a lot of exploration on planets requires automated and remote operating systems, particularly automated."

Many self proclaimed robotics experts will insist that you'll always need humans nearby to fix the robots. I agree, but I define "nearby" differently to them. The Moon is, on average, 1.28 light seconds away from the Earth. The teleoperation workflow used to operate driverless trucks and trains, and sensor-fitted "smart drills" can also be used to operate repair robots. Highly articulate robots like Robonaut 2 can be on the Moon faster than a human return and can be operated to do any useful task.

These techniques are being perfected on Earth because they are economically valuable. Simply, it's cheaper to hire office workers in Perth to operate the equipment remotely than it is to attract and house on-site workers. If this is true for Australia then how could it ever not be true for the Moon?

If we want to make a sensible argument for why we should be sending humans into space, we need to base that argument around the future homes for humanity, not mines.

Desperately Seeking: Moon First Advocate

2010-07-13T19:41:00.002+10:00

As it seems Paul Spudis isn't going to respond I am left without a sparring partner. Anyone who wants to pick up the gloves and make the case for returning to the Moon, come at it. The ground rules are simple: you must make an argument as to why we should return to the Moon first. It would also be good if you could explain how NASA can do it within a time frame that can be sold politically and within the current budget profile, but I'll settle for a why that makes sense. Note that if you just preach the dogma of someone else, you're unlikely to be able to defend it, so, please, only apply if you've got the stones.

Space Crack

2010-07-12T12:02:00.004+10:00

Back in 2006 Elon Musk famously said:

"I don't believe in the mining of stuff in space. The transportation costs are so horrendously high that I don't think there's anything… if there were packages of purified crack cocaine in orbit right now, I'm not sure it would be financially viable to go and retrieve them"

Which is ironic when you consider that it was at the unveiling of the Dragon that he made this famous quote. According to a recent presentation a Falcon 9/Dragon flight for robotic servicing would cost ~$80M. This includes launch vehicle, Dragon spacecraft, operations and recovery. It doesn't include the robotic arm, so let's include $5M for that.

The Dragon has a downmass of 3000kg. Per kg, that's $28,330. The street value of cocaine hydrochloride powder is $80-$100 per gram, or ~$80,000 per kg.

As such, in just 4 years SpaceX has managed to make the Space Crack market profitable.

(and Platinum $49,187/kg, and Gold $38,838/kg).

Flight To An Asteroid With SpaceX Hardware

2010-07-11T20:31:00.007+10:00

John Hare has an article about commercial beyond Earth orbit exploration in a world where cheap access to space has lowered the cost of a kg to LEO to $1000 or less. But I think it begs the question, how much does it cost now?

Warning: contains Machiavellian humor.

The biggest problem with commercial human beyond LEO flight right now is the lack of an affordable LH2 upper stage. In SpaceX terms: they don't have Raptor yet. But hey, no-one ever said you have to use LH2/LOX stages to go beyond LEO.

If you're aiming at an asteroid at an optimal time, there's at least one target you can hit with only 2.8km/s of delta-v from LEO, and 1km/s of delta-v to rendezvous with the asteroid, 2006 RH120. (Note that you can divide this up any way that makes sense to you, but more than 1km/s of delta-v at rendezvous is probably undesirable. For a flyby of 2006 RH120 you need 3.733km/s). See this list. Personally, I'd rather aim at 2009 BD as it is almost always "close" to the Earth.

Now the vehicle. Let's say a Dragon with a full service module, crew of 2 or 3 and some supplies: that's 10t. Even in the ISS servicing configuration it has sufficient delta-v to do the 1km/s delta-v rendezvous, and do the 1km/s delta-v needed to get back. Slowing down when you get to Earth orbit will be a dicey situation, but if you can burn off some delta-v with a lunar flyby then the PICA heatshield on the Dragon should be sufficient to get us safely back on the ground. But hey, who said anything about coming back anyway.

Using Kirk Sorensen's great formulas, the initial mass in LEO will be less than 27t (for anyone who cares, I'm using lambda=0.0133707, phi=0.0216, ISP=342s). This means you need about 17t of fuel, minus tankage, and that's not so bad. First flight will be the Falcon 9 to deliver 10t of LOX in an insulated tank payload. Depending on how much boil-off there is before the next flight, and taking into account the mixture ratio, the next flight will carry 5200kg of RP-1 and 4800kg of LOX in payload. Both the upper stages will remain SpaceX's, so they can reuse it or whatever they think they can do with it.

Finally the manned Dragon is launched to join up with the propellant tanks. Unlike the other two flights, ownership of the upper stage is transferred from SpaceX to us, as is the Dragon, but I hear they're prettimuch assuming that model for GTO flights, so it shouldn't be a problem. And they can have the Dragon back if they really want our smoking corpses, uhh, I mean, ya know.

The entire stack heads off to the asteroid. Note that it's the upper stage of the manned Dragon flight that is acting as the trans-asteroid-injection stage. Depending on how close the target is, it's a few month voyage. If you want to get fancy you can take along a really long tether and swing up the vehicle to get artificial gravity.. but remember that it'll eat into the Dragon's propellant mass, reducing contingency on rendezvous.

It's quite an adventure, so what's the price tag? The two tanking flights are just stock Falcon 9 flights at $56M each. The manned flight is probably going to be something like $150M. The tank hardware with its insulation and such is in the noise. All up, $265M.

That's a lot of money to go asking a venture capitalist for. You're going to need a pretty fancy view graph presentation to convince them that you can pull it off without dying horribly, do it better than a 1t robotic probe that could be sent direct on a single Falcon 9 flight, and bring back something worth at least 10 times as much as it cost to execute [the crew, no really, just kidding].

Book Of The Week: Stephen Baxter's "Manifold Time"

2010-07-10T10:28:00.002+10:00

The Book Of The Week this week is Stephen Baxter's "Manifold Time". The reason I love this book: rugged individualism. Sure, there's other great threads in this book and some interesting cosmology, but the memorable part of this story is the huge balls on the main character.

Reid Malenfant is an unapologetic space cadet and serial entrepreneur, who has a plan just crazy enough to work: he's going to claim an asteroid. With a shout out to Robert Heinlein he ignores a recently passed law preventing his liftoff, not to mention a few laws related to non-proliferation of nuclear materials, and heads off to his very own squid-infested home among the stars.

Oh, I didn't explain the squids did I? :)

Buy it on Amazon.

Imagine Wernher von Braun Had Won

2010-07-09T10:24:00.002+10:00

Imagine the Apollo follow-on wasn't Skylab, it was the construction of a Mars ship.

Back in the early 70s they had absolutely no appreciation for the radiation environment. Aerobraking on Mars was considered unworkable by some and trivial by others - Viking would prove both wrong but not until the mid 70s. Nuclear thermal was already a political dead duck but maybe it could have been resuscitated for an EOR mission configuration, but it's still impulse, ion engines were shelved in the early 60s as impractical, hall effect thrusters were secret Russian business. Long duration spaceflight was a backwater of scientific knowledge, as was most space medicine - some would say it still is - the bone loss problem was certainly an unknown unknown. In-situ resource utilization was a complete non-starter.

So, the good news is they wouldn't try to build Battlestar Galactica. They'd go with a capsule and a lander, but bigger and heavier than the Apollo LM and with a heat shield. They'd use a nuclear rocket which means they'd need to develop near-zero-boil-off cryogenic stages (woo! we don't even have that technology!) both for return and to mass hydrogen propellant in Earth orbit. The mission would be opposition-class and the goal would be flags and footprints.

As was always the case back then, the engineering would be in advance of the mission plan. Those nuclear stages would be ready to go before the need for them. The shakedown cruises would probably be to lunar orbit and they'd be disposed of on the Moon with a chemical stage providing the final insertion into Earth orbit. The Viking mission schedule would have been advanced to act as precursors, scouting for landing sites, etc, much like the Surveyor missions did for the Moon. The lessons learnt on the heat shields would be integrated into the lander modules.

By the late 70s the interplanetary cruise duration would be known and in the early 80s the rude shock of long duration flight effects on the human body would be so obvious that even the damn-the-doctors-full-speed-ahead culture of NASA in those days wouldn't be able to deny it. Bone loss would be a significant threat to the continuation of the program. If astronauts have lost 80% of their bone mass by the time they get to Mars, they can't land and they can't plant the flag.

A short arm rotating inflatable habitat would be the most popular solution. Ever since the 40s it was considered the obvious solution to providing artificial gravity and the only thing keeping it out of the program so far would have been the importance of establishing the Mars program as separate to the Station program, which would be starved for funds by now. Begrudgingly, the two programs would be merged, but the delays would add at least 5 years to the schedule.

So, around the early 1990s the epic voyage to Mars could begin. It would take 1.5 years to travel to Mars. After a 3 day checkout in Mars orbit the crew would descend to the surface where they would plant the flag. They would spend 12 days on the surface with regular resupply from the crew left in orbit, giving them time to collect samples, and do some exploration with Apollo-style open rovers. Leaving that single site they would return to orbit, to aid the 5 day preparation effort to return to Earth, another 1.5 years later.

By the mid to late 90s the program would be canceled after a single flight. The crew habitat and spent propellant tanks would be re-purposed as a low Earth orbit space station. Perhaps there would be some cooperation with the on-going Russian space station program. By early 2010 perhaps people would be asking why we never went back to Mars.

This is my alternate history, if you'd like to read another account, you can't go past Stephen Baxter's "Voyage" which speculates on a NASA where John F. Kennedy was merely wheelchair bound not killed. It's a great read, check it out.

Dr Paul Spudis Continues To Baffle Me

2010-07-08T18:55:00.004+10:00

No-one ever accused me of being subtle. I'm happy to clearly state my opinion and support it with what, I hope, is persuasive argument. As a result, subtle people tend to confuse me. That's right, along with all the other things I have accused Paul Spudis of over the last year, I'm now accusing him of being subtle: painfully subtle.

Over at Spudis's blog he rants and raves over the definition of "misconception" and manages to fit in a plug for what I guess is his position..

The purpose of lunar return under the VSE is not to collect rocks or relive past space glories. Simply put, because we can't take everything with us, humans must learn to use what we find in space to create new space faring capabilities, starting on the Moon. And our goals are not simply Mars, but everywhere – wherever human presence is needed or desired. Using the resources of the Moon (specifically, making consumables and propellant from lunar materials) enables routine access to all of space – not merely for science, but for economic and national security interests as well.

But I wouldn't dare suggest that's the entire position of Dr Paul Spudis because, as I said, he's very subtle ya know. In the comments, "Alan" asks:

So why not send a robotic ISRU demonstration first?
In the meantime build the orbital "gas stations" (1st @ LEO & 2nd @ EML-1) where, if the ISRU demonstration is successful, the LH2/LOX can flow from newly-built Lunar surface ISRU plants to EML-1 and onwards to LEO.
If Lunar ISRU does not pan out, then ship LH2/LOX from Earth to LEO and onwards to EML-1.

What is wrong with this?

Hey! That's what I said! But unlike when I asked, Spudis has responded to Alan:

Where do I argue against that?

As for propellant depots, I think that they make sense if we can supply them with propellant made from space resources, in this case, propellant derived from lunar water. If we end up launching all the propellant from Earth, then nothing is fundamentally changed, except to eliminate the need for a heavy lift launch vehicle. But you still have to lift all your supplies from the bottom of the deepest gravity well in the inner Solar System. We know that will always be a costly task — the real leverage in space transportation comes from freeing ourselves from that necessity by using local resources. That's where the biggest payoff and the largest, most significant unknowns are. Thus, that is where I think we should concentrate our research efforts.

See what I mean? He's so subtle! Paul, buddy, are you just completely unaware what Alan is saying or are you deliberately missing the point so you don't have to address it?

Here it is, as unsubtle as I can possibly make it:

Why do humans need to return to the Moon to get resources to make "consumables and propellant", if robots can be sent to do that instead?

I will continue to yell this question from the rooftops until the Moon First advocates explain why NASA should waste time building human lunar surface capability when they could be focusing their limited time and budget on developing human interplanetary cruise capability.

A capable lunar lander suitable for human use will cost as much as the heavy lift vehicle required to get it there.* On the other hand, a robotic lunar lander is under development right now, and will be launched on existing commercial boosters. In fact, a few hundred or more robotic landers could be sent to the Moon for less than the cost of human return.

ISRU demonstration followed by full scale production of "consumables and propellants" and returning them to EML-1 or even LEO is clearly a task for the robotic exploration program. Combined with the Cryogenic Propellant Storage And Transfer Flagship Technology Demonstration mission, NASA can very quickly build up in-space infrastructure for going beyond LEO.

This can completely eliminate the need for a heavy lift booster, meaning NASA could use existing commercial boosters and freeing them to focus on developing the other technologies needed to go to deep space, and develop landers which are suitable to carry humans. Perhaps even reusable landers which can be refueled on the Moon and in space.

Dr Spudis? Are you there? I'm waiting..

* Rand disagrees with me on this, see the comments below.

Walt Cunningham Advocates New NASA Goals

2010-07-07T22:57:00.002+10:00

On the 4th of July former astronaut Walt Cunningham appeared on the Talking Space podcast to discuss NASA's future and other topics.

Cunningham fundamentally disagrees with everything NASA is doing under the new administration. He thinks the shuttles should not be retired (although he acknowledges that the new administration inherited that situation) and should be evolved into a new vehicle. He accuses the White House administration of just wanting to cut the budget of human spaceflight altogether and alludes to activities which support this theory.

Back in March he sent a similar statement to a public mailing list I'm (still unfortunately) on:

"Lest there be any mistake, I believe Obama's removal of NASA from operation of the agency's own human space program is a major mistake. It was not an effort to improve our space program; it was purely to cut expenditures on something in which Obama has no belief. It was the second worst decision in NASA's history; the worst being grounding of the Space Shuttle without a replacement waiting in the wings."

Exactly what Cunningham is talking about here is anyone's guess though. What program is he saying Obama has removed NASA from operating? It's not the Shuttle program.. he specifically says so. Perhaps he means Constellation, but NASA is neither being removed from operating that program nor does he consider that program to be a "replacement" for the Shuttle. Oh well.

So it may come as a surprise to hear that Cunningham appears to support a number of the new NASA administration's policies and goals.

On NASA's ongoing attempts to shut down the zombie Moon program called Constellation he says:

You asked, did I think the Constellation program, as conceived was the right way to go. Well, we're getting into a different area here and I'm one of those you would say was not a wild enthusiast of the Constellation program as it was formulated but for different reasons than some other people were. For example, I've never been one that wanted to spend a lot of time setting up a base on the Moon. I want to just keep pushing on out to Mars, but there are other people who would argue just as aggressively that the Moon is a good thing to do.

To me, this is a fundamental part of the "Obama space vision", not going back to the Moon right away. He goes on to say that Constellation as an overall approach was flawed.

The Constellation program, it ran into a lot of problems because there was a lot people out there who had a different concept. [..] If it was me and I got the money to continue Constellation I would suggest that they have another legitimate - in-house - study of various alternatives of accomplishing the Vision for Space Exploration. Give some of these other people a chance to find out why their approach wasn't the one that was successful.

Ok, I thought, maybe his problem was just that Constellation wasn't shuttle derived enough for him, and he really doesn't care where we go. But no, when asked about going on to Mars as an alternative to going back to the Moon he emphatically agreed that was the best goal. And then went on to say:

The only real deal breaker at the moment is the radiation exposure. That one's a real challenge. And we're talking about propulsion systems that will speed up the journey. Of those, no-one wants to talk about the one that would probably have the best chance of the soonest on, is some kind of nuclear propulsion.

You know Walt, this administration is the first in decades to even suggest restarting the nuclear propulsion program. The Solar-Electric Propulsion Flagship Technology Demonstration pathway turns into a Nuclear-Electric Propulsion program around 2022.

I think if we're really committed we would be able to go with advanced propulsion systems, we'd be able to survive trips of 2 1/2 year missions. I wouldn't recommend landing on the surface. The difference in cost and challenge is several fold bigger in doing that. But we could go out to Phobos and to orbit Mars and come back and I think we could do that successfully.

Woah, woah, woah. You're advocating the Flexible Path there buddy.

To me, it seems Walt Cunningham really wants to believe Obama and get behind the new NASA administration but two things are holding him up.

First, he believes NASA needs more money and so he's against any President who won't ask for a significant increase. Even though NASA has never gotten much more money than they get now - even during Apollo - just ask Bob Zubrin that question sometime.

Second, the Shuttles are being retired and he loves them. Building a shuttle derived vehicle is a nice idea, but it's just too damn expensive. Cunningham addresses this in the podcast by saying people who say that - like me I guess - should look at some of the techniques that have been proposed over the years to lower the cost. Well, as the statement was directed at people like me I'll respond.

If you listen to the very interesting interview with Bobby Block from the Orlando Sentinel the other day you'll hear an anecdote about the Ares I program. The Ares I is the most shuttle derived part of the Constellation program and as such I think is relevant. Block explains, an engineer who had worked on the Delta IV project gave a presentation at NASA in which he proposed that the pad for the Ares I use a highly automated propellant handling system like that developed for the Delta rocket. The NASA people balked at the suggestion as their equipment would not be able to interface with it. Equipment that hadn't been updated since the early 80s.

Fundamentally, the Shuttle program is so obsolete and the culture is so entrenched, that innovation is stifled on a daily basis. There's a reason why so many of those great ideas to improve the Shuttle never got implemented, and the only way to get rid of it is to burn it to the ground and start again.

Hopefully, with a focus on encouraging technology development and continuous improvement this time.

Living Inside An Asteroid

2010-07-07T10:30:00.001+10:00

Deriders of the new NASA direction have latched on to the announced human asteroid mission in the 2025 timeframe as something they "can't imagine" and therefore is not worth doing. Of course, the administration is talking up the "science" that can be done on an asteroid, and how this could better inform us should the need arise to divert or destroy one that threatens Earth. This is good politics as nothing motivates like fear, but for those of us who think the human spaceflight program is really about preparing us to live at the future homes of humanity, asteroids would seem to be just a stop on the way - I disagree.

As I've written previously, the new NASA direction isn't about asteroids - it isn't about destinations - it's about going and specifically, it's about going to Mars. I'm not sure NASA knows yet why they're going to Mars, but they're focusing on the technology to get there and get back safely, and some of the stepping stones along the way are asteroids. As such, although I will often advocate that I think asteroids are a much better future home for humanity, I recognize that in terms of the battle lines of this debate, asteroids are neutral or worse, disposable.

So how does one live on an asteroid? I've regularly heard this question asked by intelligent people. They point out the low gravity and how with just a misplaced step an astronaut could be hurtled into escape velocity and lost forever! NASA's mission to an asteroid will most likely be conducted on the surface, so this is a real risk, just as it is for astronauts conducting spacewalks on the International Space Station. However, the settlement of an asteroid would have little use for the surface, except perhaps as a place to lay solar panels, as all the interesting stuff happens below the surface.

The primary reason is radiation. Just like on the Moon or Mars, humans will need to live underground to provide passive protection from galactic cosmic rays and solar storms. On Earth (and Venus) the predominate protection from radiation is provided by the atmosphere, miles and miles of it. To achieve the same level of protection only a dozen feet or so of regolith is required.

Robotic probes will be sent ahead of NASA's human mission to an asteroid. More than likely, only an orbiter, but a much more capable robotic lander makes a lot of sense. For the long term settlement of an asteroid, it will carry essential drilling equipment which it will use to drill straight down. After digging down for a while, the robotic drill will turn some significant angle and keep drilling. The hole it produces need only be big enough to maneuver a crew module into without bumping the sides - once they arrive, weeks or months later. The right-hand-turn the drill makes is sufficient to protect the crew from radiation, which can only move in straight lines. If mirrors are installed on the turn the crew can enjoy natural sunlight and a view of the stars.

Having secured the safety of the crew from ionizing radiation, they are now free to get to work. Using drilling tools the astronauts can prospect deep into the core in search of the richest metals, or collect volatiles which can be purified into drinking water or oxygen for breathing.

Soon, they'll dig a long circular tunnel with a radius of at least 894 meters. The outside edge of the tunnel is lined with metal track. A simple electric train runs the length of it, completing a full circuit in just one minute. On a parallel track the astronauts enter an open carriage which accelerates them up to rendezvous with the ever moving train. As they speed up the astronauts feel the gentle pull of centripetal force as it builds to a full Earth-standard gravity.

As the astronauts step onto the train they cease being astronauts and become settlers. They now have access to resources, protection from radiation and a full Earth-standard gravity. The colony can now grow. The train can be extended compartment by compartment and deck by deck to accommodate the growing population. Excess metals and other materials can be exported to other settlements in the solar system.

Another one of the things the settlers may wish to do is to place airlocks on some of the tunnels that lead to the surface and place transparent plastic material or even glass over the ones dedicated to bringing in natural sunlight. That way the entire internal space of the asteroid can be pressurized and the settlers will be free to work and play in zero-g without spacesuits.

Here's an animated gif of humanity's future home inside the asteroids.

Imagination is a precious part of space advocacy. Yes, we must guard it with scientific skepticism but not so much that we're afraid to dream.

The Completely False Choice

2010-07-06T14:52:00.002+10:00

During an interview on The Space Show Jeff Greason described the Flexible Path as a pragmatic approach to human space exploration when considering NASA's limited budget. Towards the end he says:

The question is not "do we or don't we go to the Moon", that's a completely false choice. The question is do we structure the program, for the same money, in a way in which - in addition to going back to the Moon - we get asteroids, Lagrange points, maybe a Mars flyby, and we build up deep space experience that we're going to need for Mars, instead of waiting 20 years and hoping that the public's enthusiasm can be sustained.

The message here is that the Moon and Mars both require landers and it's hard enough just trying to get there with a limited budget. So, assuming NASA isn't going to get double as much money, it needs to find a way to do with what it's got. This is a fiscal reality. Those who say "Constellation can be fixed" or who say "I don't think landers are all that expensive" are simply in denial.

If we choose to delay building a lander, we free up the funding to focus on interplanetary cruise capability - that is, sending astronauts beyond the Earth-Moon system and returning them safely. Where exactly the astronauts visit while they're "out in the black" is kinda irrelevant.

Yes, they can visit the Sun-Earth Lagrange points and do servicing on sun observing satellites. Yes, they can go to asteroids and do scientific investigation that may help deflect a threat to Earth one day. Yes, they can go to the moons of Mars and do more science. Yes, all this will engage the public and inspire kids to study science, technology, engineering and math. But these are just nice benefits.

The real goal is to demonstrate that the spacecraft can take us anywhere we want to go and, in particular, that it can take us to the future home(s) of humanity.

During this development process NASA's robotic exploration program will continue. Including exciting missions to the Moon to demonstrate the kind of teleoperated robotic vehicles that will be operated on the Mars surface by astronauts in Mars orbit - perhaps to do a sample return mission.

Later, the required landers can be developed so they are safe, refuel-able and re-usable. They can stay permanently at their destination - Moon or Mars - so we don't have to carry them backwards and forwards to Earth every trip. NASA will be economically free to build infrastructure to encourage the commercial delivery of that fuel from where-ever it makes sense: Earth, the Lunar surface or the Mars atmosphere.

Eventually the NASA demonstrations will give way to commercial activity. The economic sphere of influence will expand into deep space. Space-based solar power and asteroid mining will seem inevitable when a solar-electric propulsion vehicle can take astronauts to visit an asteroid as a mere stepping stone to greater things.

Colonization of the inner solar system will surely follow.

There's No Business Like Show Business

2010-07-05T13:14:00.001+10:00

That is NASA's attempt at public outreach.. and I've yet to see a single newspaper link to it or report it. If you watch it, you can see why. Whenever Lori Garver or Rob Braun is about to explain what the program is about they get cut off.

It's all so glossy and vague.. most the time I think they juxtapose the wrong images with the words.. like "we plan nothing less than to create the future of spaceflight, now" cut to a shot of the Shuttle liftoff.. wtf? "After the safe and planned retirement of the space shuttle fleet.." ohhhh, is that what that shot is for? Wow, someone failed film school.

Then they gotta say some stuff about the ISS and how great it is and fuels the international cooperation and blah blah blah. And while you're being bored by justifications for the ISS program they slip in "we're trying to make this more commercial" and private companies. Yawn, sorry, I fell asleep there, did you say NASA will focus on beyond-low-Earth-orbit, wow, that sounds great.

"We will prepare astronauts for longer trips in space" while showing what looks like a transhab module.. but only because I've seen a hundred graphics of transhab modules and I actually know what they are. I'm pretty sure the public has no idea. Why are those astronauts standing up if they're in space.. hey, that's one of those Moon base transhab modules isn't it?

"While working cooperatively with other space faring nations".. juxtaposed to some big rocket lifting off with NASA/ESA/JAXA logos on it. Garver and Braun chat about how great their international and industry partners are.. we see logos and hardware of Boeing and SpaceX.

"The agency will begin work on transformative heavy lift technology that will lead to a new rocket to carry astronauts beyond Earth orbit".. and then they show the Ares I-X launch... W T F?

"And development will continue on the Orion crew capsule to provide standby emergency escape capability for the space station" .. then Cook says "this is turning over access to LEO to the commercial sector while we focus on the broad range of technologies that we have to have in place before we can go long distances to Mars". Arrrrghhh! Orion Lifeboat is what you call the commercial sector? Are you mad? No, they just took what you said out of context and used it for political justification, sigh.

"Once the stuff of science fiction, new technologies being developed by NASA and its partners will revolutionize spaceflight" .. and we're shown Robonaut 2... cause that's relevant. Don't get me wrong, I think Robonaut 2 is awesome and all and look forward to seeing it do some useful tasks, but I don't see what it has to do with "spaceflight".

"We are investing at a greater scale so we can actually get there quicker.. and we'll start testing them in space.. we have demonstration flights that will be demonstrating these technologies as precursors before we put them into human vehicles" .. and we finally see some BIG in-space interplanetary cruise vehicle. How big is it? It's this big:

That's pretty big! "New approaches to propulsion will free us from Earth's gravity, and send us further and faster into the Cosmos". Uh huh. Ok, what you mean is that with new technology we'll be able to go beyond the Earth-Moon system and actually get back without killing the astronauts, and do it for cheap enough that it won't fizzle out and die after a few missions like Apollo did. Oh wait, you didn't say any of that.

"Spacecraft will refuel at depots in orbit." Wow, that actually looks like a propellant depot might!

"New techniques for rendezvous and docking will allow us to construct the spaceship of the future." And now the public has no idea what you're talking about, congratulations.

"Astronauts will visit and live in lightweight inflatable habitats" ok, yeah, I guess so, whatever you're talking about Mr NASA man.

"And live off the land at their destinations" What? You're showing me a picture of the Moon with a buggy driving up to something.. oh, it's some sort of dump truck delivering 4 or 5 grains of dust to big gold blob! Yeah, I have any idea what the hell you're talking about there. Anyway, clearly the Moon must be one of these destinations you're talking about. I'm so glad you've cleared up that whole "been there done that" thing for us... sigh.

For some reason Braun talked over the last bit saying something about "innovation is the American way", go team! And that NASA doesn't have a monopoly on innovation, so we're back to talking about "partnering with the commercial sector" and we're shown shots of SpaceX's Dragon and the Dreamchaser docking at the ISS. There's no logo on the Dreamchaser, and it looks sufficiently like the Space Shuttle that I'm sure there's at least some of the viewing public that is saying "huh? They're selling the Shuttles or something?"

"By nurturing this growing American industry of commercial space access, NASA will create new jobs, while freeing itself to do what it has always done best: explore the mysteries of space." Gah.. first of all, haven't you already said this? It was all the way up there with the Orion Lifeboat.. oh right, you didn't mean to associate the Orion Lifeboat with commercial crew.. oops. NASA will create new jobs? Really? That's how it works eh? I guess it's kinda like how NASA creates all those spinoffs that it just provides a little seed capital for and external contractors actually do all the research. Anyway, while you're telling me how NASA is now freed of all these jobs they can explore the mysteries of space, what are you going to show me?

Remember what I said about film school? You don't show a picture of a robot landing on another planet after you just said you're going to offload jobs on the "growing American industry of commercial space access". You can't just cut stuff together ever-which-way and expect people to know that you're starting a new segment. Oh well, let's get back to this terrible promo video.

"Robotic scouts like the Mars Science Lab, and observatories like the new James Web Space Telescope, will comprehensively explore our solar system and the galaxies beyond." Wow, so what's the point of having humans up there then? And btw, the MSL (now called Curiosity) is not a robotic scout.

"As always, NASA vehicles will do new stuff to further unlock the secrets of the universe.." or something. Allow me to translate: we're in the business of doing "science" and nothing else. Curiosity, JWST, manned spaceflight, it's all the same, with the same goals and that goal is "unlocking secrets". This is the message NASA is sending to the public: it's science, fund us. The problem with this model is that sooner or later people with a brain figure out that if you take all the money out of the human spaceflight program and dump it into the robotic spaceflight program you can do a lot more science. In fact, the decades of investment that you're going to need to put into technology development to get people to Mars could literally flood the red planet with rovers. So every time NASA equates human spaceflight with science they do human spaceflight a disservice.. please, STOP IT. Human spaceflight is not about science, that's just a nice side-benefit.

"Closer to home, the President's plan will strengthen our efforts to study and protect our home planet. An expanded suite of Earth observatories will expand our understanding of climate change, and weather and natural disasters" and all that stuff you FEAR and need to be PROTECTED from through STRENGTH. "NASA programs and spacecraft will also stand vigil against potential threats to our planet." Wow, someone read the survey that said most Americans think the best reason to have humans in space is to protect the Earth against asteroid attack. That must be why we're going to an asteroid right?

"An agency wide effort is under way to chart the path of asteroids and other Near Earth Objects". Oh wow, maybe you did go to film school! "And NASA satellites are studying the sun to better predict space weather." Remember, weather? You're afraid of weather.

"In aeronautics, new technology investments will develop the next generation technology system for the entire nation, that increases safety and is friendly to the environment". Yeah, look, the whole aeronautics side of NASA is fundamentally awesome and, of the few people who actually know about it, no-one has a problem with it. Carry on.

"These accomplishments will inspire a new generation of scientists, engineers, and explorers." Lots of stuff about inspiring kids.. which I'm sure it does.. but it's so not NASA's job to inspire kids, and the whole focus on it is received cynically by most kids over the age of 16 cause the simple truth is: there's no money in it. If you really want to inspire kids to study to be an engineer, show them how they can get rich by doing it.

"The agency will sponsor new competitions that foster ideas and innovation for new leading edge technologies and new industries." Hey look, Dave Masten! Do you get the feeling we're getting near the end of this video?

Braun: "We can take the intellectual capital at the NASA field centers and we can turn it loose on some of societies grandest challenges." I've heard this a couple of times and it's pretty shocking that it is being said outright. What they're saying is that rather than laying off civil servants at NASA they're going to give them work that is completely unrelated to NASA's charter. Specifically, this means climate change study.

Lori: "We're going to look back on this time, I hope, and recognize that we opened up the solar system for humanity." Wow, that sounds really interesting Lori, tell me more... oh, they cut away again.

Bolden: "I'm really excited at the things we're going to be able to do cause we now have money to put into research and development of the technology we need to accomplish the goals we set for ourselves." Hey, goals, they sounds good, what were they again? I've been listening to all this Did-you-know-NASA-also-does stuff for that last 4 segments that I completely forgot.

Bolden: "Our goal is to go away from the planet. We want go to asteroids. We want to go to Mars. We want to go back to the Moon. We want to do other things. We want to be able to fly higher and faster." Why? What's it for? Oh, that's right, science, it's for "science".

"Both flexible and sustainable, the nation can start moving today towards these challenging and inspiring goals". What does that even mean? "America's space exploration program will advance new frontiers and provide inspiration for the world." Gah, you almost said something there! "Frontier", that's a nice word. Unfortunately I think it means as much to you as "flexible", "sustainable" and "inspiration" does.

Bolden: "We're going to turn science fiction into science fact." And I'm going to roll my eyes like you roll that big spacecraft around.

"Exploring the universe while better understanding our home planet." Remember? NASA is relevant to national needs!

"In a new era of innovation and discovery."

Worst promo video, eva!

Let's see if I can do better..

And, unfortunately, that's the best I can do without the source material.

Reselling Mike Griffin

2010-07-04T11:53:00.003+10:00

Back in 2005 Peter A. Taylor wrote on then current NASA Administrator Mike Griffin's revisioning of the Vision for Space Exploration. In many ways, Taylor's interpretation of Griffin's vision is reflected in the new NASA direction, and one has to wonder if the opponents of "Obama Space" have any idea how much pedigree that vision really has.

As Taylor writes, it all goes back to the intricately detailed study "Extending Human Presence into the Solar System" (July 2004, Planetary Society) co-authored by Owen Garriott (that's Richard Garriott's Dad!), Bill Claybaugh (now senior director of human spaceflight for Orbital Sciences), John Garvey (Garvey Spacecraft Corporation), Tom Jones (the former astronaut, not the sexy singer), Charles Kohlhase (JPL), Bruce McCandless II (another former astronaut), Will O’Neil (independent defense and space consultant), Paul A. Penzo (former JPL, now at Global Aerospace), and Mike Griffin.

The paper advocates a three stage exploration plan:

Phase One, access to LEO

Shuttle-Orbiter return to flight (RTF), complete the ISS through at least "US Core Complete"
Select and demonstrate launch vehicle for CEV
Demonstrate early CEV use for crew transfer at the ISS
Negotiate with international partners to obtain best way to transport remaining heavy modules to the ISS
Retire Orbiter as soon as above steps are completed
Costs distributed across full Exploration window

If we were reading this map in a vertical orientation there would be a big red spot saying You Are Here. Except for that whole "demonstrate crew transfer to the ISS" part.. schedule slippage due to rocket redesigns have a tendency to throw these things out of wack. But we have to move boldly forward to:

Phase Two, interplanetary cruise

Develop interplanetary cruise capability; uprated CEV, and necessary additional modules for the destination selected
Ensure HLLV available, probably a Shuttle-derived HLLV
Enable lunar orbit missions, remote sensing, Rovers with sample return
Enable visits to Sun-Earth-Lagrange #2, astronomy, etc
Enable visit and study of near-earth objects (NEOs)
Enable visits to Mars vicinity, including moons Phobos and Deimos. Include remote sensors and Rover with return samples. Begin infrastructure placement. Select sites.
Select destinations as appropriate: science, public, other interests

Woah! Who's plan is this? That really looks like the so-called Flexible Path doesn't it? Lunar orbit, Lagrange points, Near Earth Objects? Trips to the moons of Mars? Using remote sensing and teleoperated rovers to do science and engage the public interest? What year was this paper written? 2005? WTF?

For anyone who says the Augustine committee just pulled Flexible Path out of the air, or that Obama was influenced by some secret cabal, or that he just wants to shut down human spaceflight (possibly the stupidest accusation in history), then I welcome them to do some actual reading, and try to improve your long term memory.

Once we have "interplanetary cruise", then what?

Phase Three, human surface landings

Prepare infrastructure for moon and/or Mars bases
Build on thorough preparation in preceding stages
Initiate human landings at selected destinations
Plan for future solar system exploration

Note that building bases is not in phase two. In fact, landing in any significant gravity well is not in phase two. This is Mike Griffin's plan.. when he got into office the forces demanded that he tack a lander on to phase two and talk up a Moon base - but he never actually asked for funding for that lander, and there was never any work done on the base.

Public Barnstorming

So what is phase two about? It's about going "out there", into deep space, for longer and longer. It's about showing the world that it is possible to send humans beyond the Earth-Moon system and bringing them safely back to Earth. In short, it's akin to exhibition flying in early aviation - sometimes called "barnstorming". The difference, as Taylor says, is that now NASA is doing it instead of the private sector, so it's "public barnstorming".

Phase two is not about asteroids. It's not about Lagrange points. It's not about the moons of Mars. It's not about "destinations".

Unfortunately, a lot of people think it is, and they don't understand why anyone would be interested in those destinations. I happened to think they're great destinations, because I'm an O'Neillian at heart, but arguing that would be missing the point.

Others agree that it isn't about destinations and they don't like that - Apollo was about a destination, and had a deadline, and they believe that without both of those NASA will just flop around like a dry fish and never achieve anything. I disagree. Destinations and deadlines are only goals and they're the short term variety. Yes, we need short term goals, but we also need long term ones - something Apollo never had.

The Vision for Space Exploration gives us a long term goal - give humanity the capability to expand into the solar system - let's not be blinded by the short term goals, that may come and go, to achieve it.

Jeff Greason Answers: Why Humans In Space?

2010-07-02T16:29:00.000+10:00

In a video over at the XCOR Aerospace website, founder Jeff Greason describes, among other things, what human spaceflight should be about and why NASA should be doing it.

I believe passionately in the value of humans in space.

One of the most overlooked findings on the Augustine committee, I think, was an inquiry into the reasons why this is so.

Nobody in Congress could care less why this is so from what I see publicly, but if you don't know why you're doing what you're doing it's very hard to discuss what the best way is to do it.

You get science from people being in space. It's a myth that you don't. You know, ask the guys at JPL if they would like to have human beings on some of these targets - they'll tell you "absolutely".

But that's not the reason you do it. That's just a benefit you get.

You get international good will from doing things in space. Especially if you do it with an international component. You know, ask the guys who run the Russian and Indian space programs if that's not true - it's absolutely true. It is a great benefit to the United States - it's hard to quantify, but it's a soft power thing.

But that's not the reason you do it. That's just a benefit you get from doing it.

The reason - in my words - why we have to put human beings in space is: You don't learn to live on other planets with robots. Space holds the future homes for humanity - we're going to live there some day if we are going to be a long term surviving civilization.

I don't think we should be afraid to say that.

I think we should be very open about saying that.

And I agree with him.