Futureastronauts sent on long duration flights to Mars or beyond will have to worryabout more risks than merely launching into space and reentering planetary atmospheressafely.
Spaceradiation, prolonged exposure to weightlessness and the psychological impact ofextended confinement inside a space ship are just some of the challengesdetailed in Naked Science: Spacemen (9 p.m. EDT, National GeographicChannel).
While muchof the material covered in Spacemen may seem old hat to dedicatedfollowers of NASA's space exploration efforts, the program provides a basicprimer of the fundamental obstacles facing astronauts in Earth orbit today andin the future.
Theone-hour program centers around a fictional colonization mission to anotherworld, necessary after our own Earth has grown too uninhabitable to sustainlife, to convey its message. Such planets could be found by the TerrestrialPlanet Finder - actually two different space telescopes which NASA hopes tolaunch between 2014 and 2020.
Spacemen touches on everything from antimatterand solarsails to controlled nuclear explosions - illustrated by a nifty video ofNASA's ProjectOrion tests that used conventional explosives to lift a mock payload - aspotential propulsion methods for a multi-generational spacecraft required tomake the long trip between planets.
Meanwhile,protecting spacefarers during their flight and preparing them for life on analien planet - including the development of more efficient spacesuits and shields against space radiation- are vital. Scientists are also studyingmeasures to put humans in hibernationand even expand human life spans, which could prove critical to thecenturies-long trip it would take to reach another Earth-like planet. Whetherit would be better to sent small familiesor young couples on such long journeys are still up for debate.
"We don'twant to have astronauts...reach their target and then not be able to perform,"says Brookhaven National Laboratory's Marcelo Vasquez, who is working todevelop better shielding against space radiation.
Among themore novel suggestions in Spacemen is the possibility of tailoring humanspace colonists to fit their new planetary homes.
Still securelyin the realm of science fiction, such genetic manipulation could prove useful toadapt human lungs to differing oxygen levels or other environmental conditions.But researchers say such changes would be unique for each planetary expedition.
"Each groupof people that goes to a different planet in a different solar system will becomea different species," says geneticist Lee Silver of Princeton University.
NakedScience: Spacemen will air tonight at 9 p.m. EDT on the National GeographicChannel. Check local listings.