Man vs. Machine in Space
The Mars landing and Big Media Matt's snarky dismissal and utilitarian follow-up got me thinking about the whole Space thing this week, and the advance word of the wacky new Moon scheme (and subsequent blogging here, there, there, and elsewhere) hasn't hurt either. My thoughts on the subject turn out to be something of a muddle (surprising no one who reads this weblog). On the one hand, as a confirmed Science Geek, I'm in favor of a space program on general principle. On the other, a lot of what passes for a space program at present is so incredibly badly run that I have some sympathy for the "junk the whole thing" side of things.
In an attempt (probably misguided) to clarify my own thinking about this, I'm going to bang out some thoughts on space exploration, and see where it goes. This will largely take the form of responding to some of the common pro and con arguments about space exploration, most of which can be found (along with a lot of witless jabber) in the comments to the posts linked above. I should also note that I am not a rocket scientist (though Jordin Kare is, and says some eminently sensible things in one of Matt's comment threads), and the following is just the half-assed theorizing of an atomic physicist.
The biggest problem with most of the arguments, in either direction, stems from confusion about exactly what NASA programs are being considered, and how much things cost. NASA has two largely separate space programs going on: one is based on smallish robot missions to various bits of the Solar System; the other involves putting humans in low Earth orbit. The relative merits of these are a subject of much debate, and a lot of the people ostensibly complaining about the pointlessness of the Mars mission are actually griping about the Shuttle program, and vice versa.
Some rough numbers, taken from NASA's web page, on the various programs: NASA's total budget for FY2004 is about $15 billion, of which roughly $5.6 billion goes into unmanned science stuff (including the Earth monitoring missions), while $7.1 billion is spent on human missions (I've lumped together research on human space flight and actual Shuttle mission support). There's another $1.7 billion spent on researching new launch technologies, and roughly $1 billion that's spent on stuff involving airplanes, and not space at all. In what follows, I'll consider the manned and unmanned portions of NASA's space missions separately.
By way of comparison, the National Science Foundation budget is about $5.5 billion, of which $4.1 billion is spent on "research and related activities," while the National Institutes of Health have a budget of roughly $28 billion, of which something like $23 billion is spent on research (using the proportions in this 2002 table). And, of course, all of these are chump change compared to Defense, Social Security, and the other big Federal budget items (see, for example, this page comparing NASA's 1999 budget to other programs).
Taking the unmanned part first, $5.6 billion on science missions is a lot of money, in absolute terms, but I find it a little hard to justify the claim, made by some, that sending robots to Mars is undercutting medical research. The entire unmanned science mission budget for NASA is less than a quarter of NIH's budget, and there are private companies lining up to shower money on medical researchers, an element that's definitely lacking for people who would like to study the evolution of the Solar System. One of Matt's commenters argues that NASA's budget would be better spent by giving the whole thing to NSF-- while it's true that the science mission funding alone would double NSF's budget, it's hard to overstate the importance of a lot of those missions to the fields of astronomy and planetary science. It's also easy to overstate the concrete importance of NSF-funded work-- most of it goes to basic research projects that don't do any more for Gil Scott-Heron's sister than Apollo did. Spending the money on robotic probes keeps huge numbers of scientists in operation, and it's not clear to me that blowing another couple billion through the NSF would cure cancer or make Moore's Law run any faster, and again, there are private companies dumping billions of their own on applied research in their own areas.
The availability of private funding for medicine and applied science brings things around to another inevitable argument: the claim that the whole space enterprise should just be handed off to private industry, who can do it all more cheaply and efficiently. Even leaving aside the questionable validity of that particular bit of dogma, there's a fatal flaw in this argument: there's no money to be made in space science. Or, more specifically, there's no money to be made in space science That information is of tremendous scientific interest now, though-- there's an amazing wealth of scientific content to be gleaned from just getting good pictures of distant planets, let alone actually landing a robot somewhere. Moreover, this is exactly the sort of thing that government funding is for. The difference between NASA paying to send probes to Mars and NSF funding early experiments in, say, quantum computing is one of funding scale only-- neither project is likely to produce anything of concrete value in the next couple of decades, but they both add greatly to our knowledge of how the universe works, and pave the way for potentially profitable operations down the road. These are the kind of long term, low yield programs that governments are well positioned to take on, and private enterprise is miserably bad at. The only private research operation remotely comparable to what NASA is doing was the old Bell Labs (in terms of doing things that were good science but had no short- or even medium-term profit potential), and they dismantled that in the early 90's because it cost too much.
In the end, then, I'm pretty solidly in favor of the government spending money on unmanned missions to distant planets. The yield is very good in terms of raw scientific knowledge, and while that money doesn't do much to better the physical circumstances of the citizenry (other than the scientists who have good jobs analyzing data from space probes), it's not like an extra five billion dollars is the only thing keeping us from achieving paradise on earth.
The manned side of things is a different story. At first glance, it might not seem that way-- after all, the amount of money involved isn't all that different-- $7.1 billion instead of $5.6-- so if blowing $5 billion on robot space probes is worth doing, it's not immediately obvious that blowing $7 billion putting people in space is any less worthwhile.
Except that the $5.6 billion spent on unmanned missions gets you information about a wide range of things-- that covers the development and operation of missions to Mars, Jupiter, Saturn and Mercury, as well as things like the recent comet fly-by and the NEAR mission that landed on an asteroid, and the Hubble Telescope, which provides an incredible wealth of information about the rest of the Universe. The $7.1 billion spent on manned space flight programs gets you information about one thing: what it's like to have humans in space.
OK, yes, there are experiments in other areas done on the Shuttle and the ISS, but there's very little done on Shuttle flights that couldn't be done just as effectively with unmanned missions. In fact, I've been told by colleagues who've dealt with them that NASA requires that any experiment destined for the manned flight program has to include something for the astronauts to do, whether the people designing the experiment want them fiddling with it or not. There's also very little that has to be done in space. When I was in grad school, we spent an afternoon trying to brainstorm ideas to submit in response to a NASA call for proposals to do atomic physics experiments in space, and we had a really hard time coming up with things that derived some real benefit from being in microgravity. I don't think we came up with anything that couldn't be done in a lab on the ground, given a little ingenuity.
(I should also note that this isn't just my own half-assed opinion-- Bob Park says the same thing, over and over again. I suppose you could attribute it to the natural arrogance of physicists, but there's really no shortage of people ready to point out that most of the science done by humans in space just isn't worth the effort.)
In the end, the only thing we're getting out of putting people in space is more information about putting people in space. Which is fine, as far as it goes, but we've been doing this for forty years now, and it's not clear that it's worth $7 billion a year to keep it up. If you want to object to NASA on the grounds that good money's being wasted, that's the money to go after.
Of course, that might change if there were some compelling reason to care about putting humans in space. A lot of commenters think they already have one (or more), and the new Moon proposal is an attempt to supply one (Gutting the unmanned part of the space program to fund more manned missions would still be foolish, though). I have opinions about those issues as well, but I'll split that off into another post.
Posted at 6:50 PM | link | follow-ups |