At Last We Know Where Uncle Dick is Hiding OutAs an old space nut, it's always thrilling to me when space exploration gets this kind of attention. The success of the Mars Spirit rover is really great, and even if I differ with the President's approach on the space program -- and suspect his motives -- it's nice at least to be discussing the issue here.
As bullish as I am in general on space exploration, I'm firmly in the robotics-remote exploration camp. It's clear that the primary motivations behind sending humans into space are political: the idea of a "vision", wanting to distract people from problems on earth with the suggestion they're part of a larger mission, and the promise of expensive aerospace projects. Sending humans into space is enormously expensive, dangerous, and until we can figure out how to get a cheap reusable space vehicle to go 200 miles and reliably return humans alive, going 20 million miles seems like a fairly dumb proposition.
I won't debunk the myth of return-on-investment from space in detail, since it's been done elsewhere, although the "for every dollar invested in the space program, $7 is returned to the economy" myth keeps popping up, so I'll do the quick version here. No doubt the Apollo program produced some economic returns and some innovations, but there's utterly no evidence that a general investment in science and research wouldn't do the same thing -- perhaps a more diverse investment in knowledge campaign would produce even more dividends. The economic conditions of today are different from the 1960s. And that $7 for $1 ratio was a cheat -- the way gross domestic product is calculated, the same dollar trickling through the economy gets counted multiple times. Here's an example: NASA pays a general contractor a dollar to build the space shuttle. The general contractor pays a subcontractor, say, 90 cents of that dollar to build the core vehicle. The subcontractor pays another subcontractor 80 cents to build the avionics system. The avionics subcontractor pays another subcontractor 70 cents to build the computer. The computer subcontractor pays a couple of subcontractors for software, chips, etc. You see how it works. The old $7 for $1 estimates were based on this kind of wishful accounting.
So, I disagree with the "human adventure" rationale because that's an elitist and vicarious approach to spirituality; I disagree with this as an economic program, because there's better ways of making economic investments; and I disagree with it as science, because robots and scientists are much better and more cost-efficient at science at such tremendously remote distances than politicians, fighter jocks, and administrators.
But the real reason to maintain a strong presence in space is, and always will be, a defensive one. No, I'm not talking Strategic Defense, which is about the stupidest and least cost-effective and most error-prone defense proposal, ever. I'm talking Planetary Defense. Not against Aliens: against asteroids.
The strong evidence of mass extinctions caused by large meteor and asteroid impacts is pretty good. The frequency from the historical record is disturbingly high in geologic and even biological time. A large enough asteroid would wipe out all mammalian life, and even a small one could provide enough disruption of the weather, crop cycles, and atmosphere to basically wipe out human civilization as we know it.
If I were running the space program, I'd have two focuses. First would be pure science, with more money for robotic exploration and less money for the very expensive and not-entirely-useful shuttle-type programs. The idea that we actually need people in orbit, or even on the moon or Mars, to learn in space is childish at best.
The second focus area would be on planetary defense. This would mean developing the technology to track and spot threats to the earth at long distances, and if necessary send robotic and human-staffed spacecraft to provide means of diverting any threats at longer distances (where the angle of deflection to prevent a collision needs to be the least, therefore would be possible with lower amounts of energy expanded.)
If we're to keep humans in space, we should do so by avoiding gravity wells. Gravity and lift is extremely expensive. The amount of weight required to lift a human and all his or her life support apparatus is incredibly high. Re-lifting them off a gravity well like the moon or Mars is even more expensive.
What we should probably focus on, if we're going to return to space in a more dramatic way, is an L4 or L5 point platform, mostly automated and robotic but perhaps with very modest facilities for a few humans, as a cheaper outpost than returning down to relatively useless gravity wells. It would provide a different vantage point, and probably a better spot for the long learning curve about living in space (as opposed to another planet, which short of terraforming -- probably thousands of years in the future, if it's even possible at all -- is just another desert as far as humanity's concerned.)
The area where these two areas should converge is not Mars, but just beyond Mars: the asteroid belt. We have only a fraction of the objects in our solar system accurately mapped and catalogued, and getting closer -- telescopically, at least -- via a space platform and concentrating on the mysteries of the origins of the asteroid belt, its behavior, and predicting the flight of its constituent parts -- that would be both an investment in science, a solid preparation for planetary defense, and, yes, if the President wants to make it thus, a grand adventure.
What I don't like about the President's proposal is this obssession with landing on Mars. NASA's actually been angling for that as a goal for 40 years, and there's utterly nothing new about it. The reasons for going to Mars in person in fact diminish the more we know about it. The more interesting parts of the solar system are the moons around Jupiter, and until we get another dozen or so probes out there (and at least land on Io and Europa), it's pointless to send humans there, either.
When I re-read the President's proposal, it becomes depressingly familiar. There's utterly nothing new there. The goals for replacing the shuttle are on pretty much the old timetable. There's nothing substantive about the Mars program, other than being a bit less cadgy about that being NASA's goal. There's nothing to encourage privatization of space or near-earth-orbit programs. And the trillion dollar cost -- quadruple that by the time the money's actually spent -- isn't even discussed relative to other costs and benefits.
Me, I wouldn't mind paying a trillion dollars if it meant we could ensure survival on earth from an apocalyptic disaster. But as with most things concerning defense and the environment, this administration has it backwards. They're like power boaters -- always pushing towards the destination on land and how to get there as quickly as possible. What we need to do is sail -- go slowly, and spend our time getting in tune with the environment of the ocean of space and not obssessing on a specific point as the destination. As any mariner can tell you, the most dangerous part of the ocean tends to be the pointy stuff around the edges, and the most interesting things are below the surface of the water.
At the same time, I'd like to see the knee-jerk reactions against space program proposals to be a little more considered. It's hard to be an environmentalist if there's no environment. I believe there's a politically palatable middle ground on space focussing on planetary defense and middle-planet science, but it's important that the dialogue continue on this and not on the basic of tasty, but ultimately useless, pork like a human landing on Mars.