Manned Space Flight

Over the past few months, several of my readers have emailed me about my opposition to manned space flight programs. The gist of these emails is surprise that I (a complete geek) would take this position, and accusations that I'm ignoring the long-term imperative for mankind to live in more than one place. A couple writers suggested that I lacked an appreciation of the romance and frontier adventure inherent in manned space flight.

Well.

I'm not actually opposed to manned space flight. I am opposed to the use of public funds for manned space flight in its current incarnation, and for the objectives set for so far. If a private company can raise the capital to pursue a profit-seeking venture in space (as several have done), then I'm all for it. I think the X prize notion for incremental technology advances (even for advances that support manned space flight) is a wonderful idea -- a relatively small amount of public funding that generates a large amount of competitive invention and development. But tens of billions of dollars spent for a useless space station, or a lunar station, or a visit to Mars? In my book, those are mind-boggling boondoggles run by an inefficient bureaucracy for no good purpose at all. Much better to either not spend those public dollars at all, or to invest them instead in something with an obviously useful objective -- such as, say, a replacement for storage batteries (one of the key problems facing alternative power technologies).

I'd also be supportive of publicly funded research to solve the two key problems with long-term manned space flight: propulsion systems and the energetic radiation problem.

Chemical rockets -- currently the only propulsion system available to lift payloads from the Earth's surface to near-Earth orbits -- are woefully inadequate for any serious manned exploration of space. They're outrageously expensive, dangerous, and (usually) badly polluting. It simply isn't practical to launch thousands of such rockets a year. If manned space operations are to become routine, this issue must be solved. We need a practical, safe, cheap lift system. Some alternatives to chemical rockets have been proposed, most notably "rail guns" and "space elevators". Both have lots of challenges, and it remains to be seen whether either can be successfully developed. It seems most likely to me, however, that the real answer hasn't even been thought of yet. I could support public funding in an intelligent way to get at an answer for this problem.

The energetic radiation problem has been discussed in the media, but it still isn't widely known (based on my own informal discussions with ordinary people). Simply put, everywhere in space outside of a planetary magnetosphere there is lots of very energetic radiation that is dangerous for astronauts -- dangerous enough that weeks of exposure is certain to lead to a high incidence of radiation-related illnesses and (if the exposure is long enough) death. The "energetic" part of the phrase implies something else: shielding is very difficult. Several feet of lead would be required to reduce the radiation to levels comparable to that found on the Earth's surface. Can you imagine a spaceship whose hull was lined with several feet of lead? Absurd, of course -- but nobody has yet come up with a good answer for this problem. Again, I could support a wise expenditure of public funds for the purpose of attacking this challenge.

So... Imagine a future where we've got a good lift system and where we have solved the energetic radiation problem. Would I then support public funding of manned space flight? I don't know the answer to that without knowing what he objective is. If it was a lunar station or a visit to Mars, my answer would still be "no". However, I think the question is actually moot -- because under those conditions, I think entrepreneurs would be raising capital to fund their own profit-seeking manned space flight. What would their objectives be? I have no idea, though I could imagine tourism, solar power, and some kind of natural resource exploitation being natural categories.

In the meantime, I believe NASA's role should be limited to robotic research missions (which have in the past ten years accomplished truly amazing things) and nurturing research on the tough challenges to manned space flight...