Wednesday, January 26, 2011

Space Colonization As The Savior Of Progress

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.

Monday, January 24, 2011

The Easy Way To The Moon

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 51.6ยบ 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 Maneuvers70
Cruise ACS10
Breaking Burn2455
Landing ACS20
Landing Site Navigation25

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

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 ;)

Thursday, January 20, 2011

UFO Evidence (or the lack thereof)

"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.


Friday, January 14, 2011

How The Politicians Think

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?

Sunday, January 02, 2011

Mars Direct Without Super Heavy Lift

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.