CAPE CANAVERAL, Fla. (AP) -- The third and final spacewalk of the current shuttle mission has ended with one issue still unresolved.
Engineers were unable to come up with a fix for a valve problem on a storage tank the astronauts finished installing on the International Space Station today. A NASA spokesman says there's no immediate need to fix the problem, since the ammonia in the tank is essentially a backup in the event of a leak in the space station's cooling system.
The two astronauts wrapped up their 6 1/2-hour spacewalk with some prep work for the next shuttle visit. The final flight of Atlantis is scheduled for May 14. They also did some picture-taking before climbing back inside.
Spacewalker Clayton Anderson said the Earth is "a beautiful place," and it's "too bad more people can't have that view." Discovery is scheduled to leave the space station on Saturday and return to Earth Monday.