astronauts to mars

The recent anniversary of Apollo 11 has sparked a revived call for manned exploration of Mars. And many have responded to that call by listing the vast technical challenges that such a journey would entail. However, some have worried that the psychological challenge of sending men to the red planet far outweighs any engineering issue.

To test the psychological effect of such a trip, the European Space agency set up simulated Mars missions where six "astronauts" were locked in a tube for months on end. The volunteers for the initial, 105-day, test have just emerged from their titanium chrysalis, and it seems like it wasn't a day to soon.

Setting aside very real concerns such as our lack of a spacecraft with suitable size and power to launch astronauts to Mars—much less the outer planets or other stars—suspended animation lingers more in the realm of sci-fi than reality. Yet the concept remains attractive, especially for longer journeys, because astronauts in a Rip Van Winkleâ€like stupor might be protected from the serious health hazards associated with distant space travel, and they wouldn’t need food—or entertainment.

A reader inquires: "Why can't we put people into some sort of cryogenic sleep and launch them to Mars -- or to an even more distant destination, like Alpha Centauri?"