by Charles Q. Choi, Special to SPACE.com
Date: 31 March 2008 Time: 10:00 AM ET
Dangerous levels of radiation in space could bar astronauts from a mission to Mars and limit prolonged activity on the moon, experts now caution.However, more research could reveal ways to handle the risks that radiation poses to space missions.The magnetic field of Earth protects humanity from radiation in space that can damage or kill cells. Once beyond this shield, people become far more vulnerable Astronauts have long seen white flashes while in space due to cosmic rays, or extremely high-energy particles, passing through their heads. A return to the moon or a mission to Mars that NASA and other space agencies are planning would place astronauts at continued risk from cosmic rays or dangerous bursts of solar radiation. Several reports in the past have outlined the potential risks.To further investigate the risks that space radiation currently pose, the National Research Council assembled experts in space and biology together. At the present time, given current knowledge, the level of radiation astronauts would encounter "would not allow a human crew to undertake a Mars mission and might also seriously limit long-term Moon activity," this committee notes in their new report today. Uncertainties remain
Still, much remains uncertain regarding the actual risks that space radiation poses for the body, explained committee member Walter Schimmerling, a scientist now retired from NASA's space radiation program. All these uncertainties mean that safety margins have to remain high, limiting how long astronauts can stay in space. This in turn could rule out a mission to Mars, as well as long-term or multiple missions to the moon."The way to deal with that problem is to reduce the margins of uncertainty," Schimmerling toldSPACE.com.To enable at the very least lunar missions with astronauts, the committee stressed that radiation biology research...