Discovery begins journey back home

The crew used the robotic arm on Discovery to scan the left wing8217;s defences yesterday. They will survey the right wing and nose cap after separating from the orbiting laboratory. 8216;8216;We are going to look at it one more time,8217;8217; Discovery pilot Mark Kelly said in television interviews. 8216;8216;But based on what we have seen so far and on what the risk is, I think all of us feel really comfortable.8217;8217;

Lead flight director Tony Ceccacci said that shuttles have been hit by space debris in the past. The odds of catastrophic damage from space debris were one in 221, while the inspection lowered the risk to one in 282, he said.