Thursday, May 7, 2009

Lonely Luna - Not Feeling the Love?

Orion capsule

The Obama administration released its formal 2010 budget proposal today, proposing about $18 billion for NASA, about a 5 percent increase. More interesting are reports that the human spaceflight program will undergo a major review, one that may end the current plan to establish a permanent moon base.

All of this is bound up with the troubles of the Ares rocket, the main component of the 'Constellation' program, the overall cost of which is now projected to run to $44 billion. That is not the worst of its problems; one recent worry about Ares is that it might drift into its launch tower during liftoff. That is the sort of thing that American space rockets used to do back around 1959 - we really ought to be past that phase by now.

Given my politics I would love to blame it all on George Bush, but like Ares that probably won't fly. The truth is that all these decisions - not just the technical ones, but the policy framework - are determined several levels down. Because the further truth is that no national US political figure, so far as I can tell, is at all clueful about space. (The one possible exception is Newt Gingrich, who alas is clueless about Earth.) There is no reason they should be this early in the 21st century; the problems they have to deal with are overwhelmingly terrestrial. By 2059 or 2109 it could be a different matter, but not yet. As a practical matter we are unlikely to have a president who knows anything about space till we have one who grew up on science fiction.

Nor am I qualified to bloviate about the Constellation program or Ares technology, since I haven't followed the technical issues at all. The only observation I'll make is that returning to Earth by parachute, as the Orion crew capsule is intended to do, is probably not such a bad idea. When I first heard the idea it sounded horribly retrograde, a huge step backwards from the Shuttle. Parachuting down sounds like an emergency procedure, because we associate it with bailing out, even though about 99.99 percent of the people who have ever used a parachute did so by intent. Space travel is not aviation. There is no reason to put heavy structures like wings on a spacecraft if you can avoid it. This is one area - by no means the only one - where the rocketpunk-era vision has led us somewhat astray. (Though I still think the Skylon concept is way cool looking.)

But what about a moon base? This is another tradition that goes back to rocketpunk days - and perhaps another one whose time has passed. The moon has two problems: It is not really on the way to anywhere, and it has at most traces (if even that) of what we need most to get anywhere, namely volatiles AKA rocket fuel. So much - alas! - for producing fuel on the moon and shipping it to L5 or Earth orbit. The fuel isn't there to ship out.

Mars, on the other hand, certainly has water ice and probably enormous amounts of it, locked in permafrost just beneath the surface. Extracting it won't be easy, but at least it is there to extract. Somewhat handily Mars also has an atmosphere, so Mars orbital tankers can return to the surface with only modest descent fuel. Even better, there are hints that Deimos, the diminuitive outer moon of Mars, may have volatiles. If so it will be the natural gas station of the inner Solar System, directly accessible to electric powered deep space craft.

Does this mean skipping the Moon altogether? Almost certainly not. If nothing else, we'll want to test our planetary-landing procedures fairly close to home before using them on interplanetary missions. Not to mention that we haven't explored the place, only barely touched it.

But it is a very poor second to Mars, and that is what our primary goal ought to be.


Anonymous said...

While a Lunar base does have many useful purposes (astronomy, research, practical expereince, ect.), you are right in that it is a secondary destination. Luna will have outposts, Mars will have colonies.

Rick said...

Another factor that plays in here is travel time. The moon is close enough that (given extensive, affordable human spaceflight) people can go to work at a moon base for, say, 90 day rotations.

Short of torch drives that is a nonstarter for Mars. Even Pretty Damn Fast electric ships will be governed by the opposition cycle, with a travel window about every two years. Tourists* and some specialists may go and return in one cycle - spending less time on Mars then en route - but any permanent base means a minimum two year stayover.

So a permenent Mars base has to be far more self-sufficient, logistically and socially, with more characteristics of an incipient colony.

*Probably the first Mars tourists will be VIPs on 'inspection' tours. But given that a few people have already paid the Russians $20 million a pop for orbital tourism, maybe not!

Anonymous said...

I've always found the arguments for Mars a little weak. I suspect any civilization powerful enough to move thousands of people to another planet would be able to terraform Venus with about a century of work. It would be a megaproject on the scale of the temple complexes of Egypt (Pyramids, lesser burial houses, temples, statuary...), but a terraformed Venus would be a much more stable place than a terraformed Mars. And any civilization willing to start a terraforming project obviously thinks in the loooong term.

But I do agree that the Moon is unlikely to have large-scale permanent settlements. Even with fast torch drives the situation gets worse for the Moon. With a good SF torchdrive the Moon becomes a daytrip, while Mars (Or Venus) remains a week or two away. It still makes sense to have temporary workers on the Moon while the planet(s) get long-term bases.

On the other hand, if there are enough tourists going to the Moon you may well get small settlements dedicated to running the tourist facilities (Ski jumps, golf courses, brothels, restaurants, etc). And since there's no real orbital 'season' to visit the Moon, the tourism trade may be year-round. The first born-and-raised Lunatics may well be a small community of service workers, surrounded by part-time miners, etc.

Sort of like Banff and loggers.

Rick said...

Would a terraformed Venus be more stable, long term, than Mars? It depends (I believe) on something we don't really understand yet, the relationship of lower-atmosphere temperature, cloud formation, and albedo. Too much water vapor and you get a runaway greenhouse. Not enough clouds and the water vapor can get above the ozone layer, where it breaks up and the H2 leaks into space. (Which may be how Venus lost its primordial oceans, if it ever had any.)

Also my gut feeling is that terraforming would take a lot longer than 100 years, mostly to build up an ecosystem rich enough to stably support complex life, e.g. us. (Someone - this is cool! - has coined a technical term, ecopoesis, for this Ultimate Gardening process.)

The first born-and-raised Lunatics may well be a small community of service workers, surrounded by part-time miners, etc.This is broadly how I suspect that colonization will happen anywhere, at least through the midfuture.

Anonymous said...

I should have been more specific. When I mentioned Venus terraforming, I really meant chemical and thermal engineering: Reducing atmospheric mass, adding stuff like hydrogen and magnesium and calcium, and reducing overall temperature. Temperature is the big problem. You need to bring the lower atmospheric temperature down to the point where it doesn't free up the carbon captured by organisms in the upper atmosphere.

Ecopoesis is staggeringly easy when you're drawing off a reservoir as large as Earth. Even full-scale ecology-building is simple: Volcanic islands do it all the time just based on whatever gets carried to them by wind and sea.

What's hard is building a tailored ecosystem, a garden ecology that matches human needs and desires. Just building a small stereotypically English stream ecology would take generations of work.

We know Mars is small enough to lose atmosphere. We don't know if it's .376 gravity is enough to prevent bone and muscle degradation. And either Mars or Venus would require a megaproject to construct a large moon to stabilize their axis.


Rick said...

Temperature is the big problemPutting it mildly! Once the heat trap is removed, I imagine it would take some decades just for the surface rocks to cool, since the heat has to be radiated into space.

Point well taken about the alacrity with which ecosystems take hold on new volcanic islands, etc. (And the distinction from 'tailored' ecosystems.) My core concern would be stability, which I assume comes mainly from having lots and lots of variety.

Surely building a large moon qualifies as a gigaproject, at least!

An interesting Venus issue would be the effect of its slow rotation rate. Years ago I wrote a crude and user-hostile planetary climate sim to test the effects of different rotation rates and axial tilt, and eccentric orbits. It is still on my old static website, but I don't know how much or little validity the results have. I'm surprised that no one 'out there' has done a better planetary sim to play with.

Anonymous said...

At some point I need to pin down some of my more chemically-oriented friends and discuss the Sabatier reaction with them. I've always thought that in the early stages of planetary engineering Venus's excess heat should be used as a power source to strip away or sequester atmospheric mass.

'Stability' in an ecosystem comes from ignoring stability in favour of dynamic instability. Which in practical terms means an ecosystem that can support a human colony is actually a group of smaller ecoregions, each with a slightly different set of plants, animals, and micro-organisms. Jerry Pournelle's comment about how most SF writers don't understand the scale of planets applies here as well: "It was raining on Mongo that morning."

The good news is that once the chemical and thermal engineering is finished, it's easy to build a planetary biosphere made up of hundreds of local ecosystems capable of supporting human settlements. All you need to do is carpet-bomb the planet with algae, lichens, planktons, lots and lots of bacteria, and let it sit. In 1-5 years you can add fungi and invertebrates, and a couple of years after that you can add farmers. Leave building the tailored ecosystems to the settlers, as a cultural project.

The bad news is that the classic SF idea of settling a world with a pre-existing biosphere is right out. There's no space for humans or our crops.

Moon building is probably a gigaproject or even teraproject. But more importantly it's a great excuse for government oversight in space. No sane civilization would let anyone fling around millions of tons of rock at thousands of meters per second without some form of oversight. Of course, the idea of an insane civilization with that level of power has some story potential...


Rick said...

"It was raining on Mongo that morning." LOL.

An eight hour drive east would takes me to about half a dozen typical SF habitable planets. Mediterranean Coast World, Foothill World, Semi-Arid Valley World, Agricultural Valley World, Mountain World, Desert World, and Gambling World. And a few hours more to DeserET World, the Mormon planet. :-)

You are right about ecological stability, which is why I regard it as more or less synonymous with 'richness,' meaning not sheer biomass but lots of biomes with a multitude of niches and species to fill them.

To borrow from a conceptually related discipline, economics, you don't want an excessively 'leveraged' biosystem. Economic depressions are bad. Ecological depressions are REALLY bad.

And your point about ruling out colonizing planets that already have a life system is hugely important. Make that HUGELY important. This has done as much as the fantasy element of FTL to turn me away from traditional interstellar settings.

Maybe I should do a front page blog post about it!

Z said...

I built a Martian in-situ rocket fuel plant some years ago, and on the making rocket fuel front, there is one major component you left out- the CO2 in the air means there are 19th century, cast-iron plumbing reactions you can do to make oxygen and hydrocarbons with plumbing-as in on your first mission, so the mission looks like a couple of Saturn Vs instead of a battlestar.

I too have been frustrated with the attention to the Moon, not because I would have any deep and abidding distaste for a stroll on the Moon, but because its a crappy destination.

Simply from the standpoint of living there for a protracted, on Mars, a reverse-water gas shift and electrolysis system will reliably make oxygen from the local atmosphere to replenish your losses. On the Moon, you want oxygen, you are smelting rocks, sans any of the handy combustion processes we use on Earth. Plastics, fuels, plants, you need carbon-bearing gas and water, which Mars has and the Moon doesn't. You want food on Mars, you set up a couple-psi tent and pump it up, and might even luck out and be able to feed it from an aquifer- do it on the Moon, and you're building it underground for the radiation shielding, hoping your CO2 scrubbing cycle is tight enough to feed it all your exhalations and you don't starve- and you probably need to artificially light the thing with the amount of micrometroid-proof transparent shielding you'd need.