NASA has decided that no repairs are needed for a deep gouge in Endeavour's belly and the space shuttle is safe to fly home.
Mission Control notified the seven shuttle astronauts of the decision yesterday right before they went to sleep, putting an end to a week of engineering analyses and anxious uncertainty - both in orbit and on Earth.
"Please pass along our thanks for all the hard work," radioed Endeavour's commander, Scott Kelly.
Mission Control replied, "It's great we finally have a decision and we can press forward."
The astronauts had spent much of the day running through the never-before-attempted repair methods, just in case they were ordered up.
After meeting for five hours, mission managers opted yesterday night against any risky spacewalk repairs, after receiving the results of one final thermal test. The massive amount of data indicated Endeavour would suffer no serious structural damage during next week's re-entry.
Their worry was not that Endeavour might be destroyed and its seven astronauts killed in a replay of the Columbia disaster - the gouge is too small to be catastrophic. They were concerned that the heat of re-entry could weaken the shuttle's aluminum frame at the damaged spot and result in lengthy postflight repairs.
The space shuttle Columbia was destroyed in 2003 when hot atmospheric gases seeped into a hole in its wing and melted the wing from the inside out.