Apollo 17's Harrison Schmitt -- a geologist at the time, and the only scientist to make the lunar journey -- served a term as U.S. senator from New Mexico, but was defeated in a run for re-election in 1982.

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Last December, one of the last men on the Moon, Harrison Schmitt, told BBC News that he believed Nasa and other government run space agencies were "too inefficient" to be able to send astronauts back to the Moon.

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