What is the greatest risk to Atlantis crew?
NASA officials have repeatedly said that the STS-125 mission to Hubble faces a higher risk of severe damage from space junk and micrometeorites. Initially, that risk was about a 1-in-185 chance, which exceeded NASA’s safety rules that call for a maximum risk of a 1-in-200 chance. Since then, NASA has found ways to reduce the risk further by flying Atlantis in a tail-first orientation with its payload bay facing the Earth as much as possible. The shuttle will also fire its engines to move to a safer orbit just after releasing Hubble near the end of its mission. Altogether, NASA’s management efforts now set the risk at about a 1-in-229 chance of critical damage from space junk, despite recent spikes in debris levels from a Feb. 10 satellite collision and China’s 2007 anti-satellite test. The current 1-in-229 chance puts the risk on par with other risks associated with human spaceflight, NASA officials have said.
