People say that manned spaceflight is too expensive and the money wasted on manned spaceflight should be redirected towards unmanned spaceflight. However this statement assumes that people are really interested in the scientific return from unmanned spaceflight. The cost of sending a spacecraft to Mars is large, usually greater than $250 million. You can do a whole lot of research on biotech, nantechnology or energy research for $250 million. The bang-per-buck for space science is one of the worst in all of the sciences. Here is another clue: Why do we send spacecraft to Mars but almost never to Venus? Venus is closer to the Earth, almost a twin of the Earth in terms of mass and size and has a substantial atmosphere. The unanswered question of why the atmosphere of Venus went into a thermal runaway should be a profound interest. Of course the answer to this paradox is clear: There is the potential of sending people to the Martian surface but it is impossible to send someone to the Venusian surface. The potential human aspect makes Mars interesting. Kill the manned program and the appeal of Mars (and the Moon) goes away. If the manned space program is terminated then the unmanned space program will also die within one decade.

Gary