Wednesday, July 28, 2010

Coding Orbital Mechanics

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.

Saturday, July 24, 2010

Dr Paul Spudis Responds - Sorta

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.

Friday, July 23, 2010

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

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

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.

Thursday, July 22, 2010

Hating On Propellant Depots

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.

Wednesday, July 21, 2010

My Reason For Human Lunar Return

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"

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.

Tuesday, July 20, 2010

CCDev Is Dead

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?

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.

Monday, July 19, 2010

A Likely Scenario

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.

Sunday, July 18, 2010

How Near Are The Near-Earth Asteroids?

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.

Friday, July 16, 2010

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

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

Wednesday, July 14, 2010

The Future Mines Of Humanity


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.

Tuesday, July 13, 2010

Desperately Seeking: Moon First Advocate


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.

Monday, July 12, 2010

Space Crack

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).

Sunday, July 11, 2010

Flight To An Asteroid With SpaceX Hardware

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].

Saturday, July 10, 2010

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

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.

Friday, July 09, 2010

Imagine Wernher von Braun Had Won

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.

Thursday, July 08, 2010

Dr Paul Spudis Continues To Baffle Me

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.

Wednesday, July 07, 2010

Walt Cunningham Advocates New NASA Goals

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

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.

Tuesday, July 06, 2010

The Completely False Choice

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.

Monday, July 05, 2010

There's No Business Like Show Business



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.

Sunday, July 04, 2010

Reselling Mike Griffin

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.

Friday, July 02, 2010

Jeff Greason Answers: Why Humans In Space?

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.