Science and human space flight

President Obama’s commission to examine possible options for the future of human space flight is getting ready to issue its final report.  They are apparently discussing seven different possible options, some that involve going to Mars, and some that don’t.  There was an interesting report in Nature last week about a recent public meeting held to discuss the various options. (Thanks to my brother Andy for pointing this out.)

Of course, I’m most interested in the implications for science, so this caught my eye:

The panel plans to cost out the scenarios by next week, and also to assess the benefits of each for 12 key areas.

One of those areas is the potential to gain scientific knowledge from each strategy, says panel member and astrophysicist Christopher Chyba, of Princeton University in New Jersey.

To that end, yesterday’s meeting was mostly devoted to presentations from scientists representing four communities supported by NASA: Earth sciences, space-borne biological and physical science, astrophysics and planetary science.

So what did the scientists have to say? Well, according to Nature one of them didn’t have much of a case to make:

Anthony Janetos, representing Earth sciences, was hard-pressed to find an example. The director of the Joint Global Change Research Institute in College Park, Maryland, Janetos hedged when panel member and former astronaut Leroy Chiao asked if the thousands of pictures he took during shuttle flights were really all that useful. Janetos said they were “marginally” useful.

The others seem to have more sanguine views of the potential for getting science from human space flight.  The astronomer Marcia Rieke naturally and correctly pointed to the Hubble Space Telescope, which has been incredibly productive and has always depended on humans in space for support.  Planetary scientist Steven Squyres says there’d be a big scientific payoff from sending humans to Mars, comparing a human mission to the Spirit and Opportunity rovers:

He said that astronauts on Mars could do in a minute what his rovers averaged in a day, and pointed out that Spirit and Opportunity had covered less ground during their entire mission than Apollo astronauts in a lunar rover were able to travel in a day.

Of course, the fair comparison is between what humans could do and what a robotic mission could do if it had the same budget as a human mission (i.e., thousands of times what was spent on Spirit and Opportunity).  I doubt very much that the humans would win out in that comparison.

I doubt that you can ever justify sending humans into space on scientific grounds.  But that’s not and never has been the reason we send humans into space.  If we send humans to Mars, it’ll be for the intrinsic awesomeness of the achievement.  Personally, I don’t think that awesomeness is worth the price at the moment.  I think if we’re going to spend upwards of $1011 on engineering and R&D, it should be on a massive investment in energy technology for Earth.  If we do send humans to Mars, of course, I reserve the right to think it’s awesome and to be excited about it.

By the way, one of the Augustine panel’s seven options is particularly baffling to me:  “what the members called the "flexible path," which would avoid the "deep gravity wells" of the Moon and Mars, saving the time and cost of developing landers to carry astronauts to the surfaces of those bodies.”

A flyby of the moon might be followed by more distant trips to so-called Lagrange points, first to the location where the gravity of the Moon and the Earth gravity cancel each other out, then to where the gravity of the Earth and Sun cancel out. There could also be visits to asteroids or flybys of Mars leading to landings on one or both of the low-gravity moons of Deimos and Phobos.

This seems to me to have most of the disadvantages of human space flight but to cut way, way back on the advantages, i.e., both the scientific payoff and the intrinsic awesomeness.

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Ted Bunn

I am chair of the physics department at the University of Richmond. In addition to teaching a variety of undergraduate physics courses, I work on a variety of research projects in cosmology, the study of the origin, structure, and evolution of the Universe. University of Richmond undergraduates are involved in all aspects of this research. If you want to know more about my research, ask me!

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