20-04-09 Space Junk Risk:1 in 221 During Hubble Repair Mission

NASA lowered the chances of a space impact,but the threat is real.When the shuttle Atlantis crew blasts off for the final Hubble Space Telescope repair mission next month,it faces a 1 in 221 chance of impacting space junk during its journey,NASA recently said.The 1 in 221 figure is an improvement over previously compiled numbers,with an October prediction of a 1 in 185 chance of debris or micrometeorite impacting the shuttle.Missions launching with a risk higher than 1 in 200 requires a special waiver to be approved of and signed before the mission can go forward.Even though the odds have gotten better,NASA researchers still say the threat from a micrometeroid or orbital debris (MMOD) impact is still a major concern.If an MMOD does in fact hit the shuttle as it heads to Hubble,there are several options for astronauts.The first option,depending on the size of the impact,is to use NOAX -- a space version of Bondo -- which would require an additional spacewalk.The second option is that NASA could launch shuttle Endeavour,which is on standby as a rescue shuttle,to retrieve the crew at the Hubble.Since the Hubble doesn't have living space like the ISS,shuttle Atlantis will take additional water and food supplies into space with them.The chance of a shuttle headed to the International Space Station (ISS) impacting space junk is significantly lower,as it floats in a lower orbit with less space junk. Hubble is currently 350 miles away from Earth,and its orbit has much more debris,according to researchers