Two spacewalking astronauts unpacked the international space station's new radiator early on Friday and started on a series of fix-it tasks as they floated high over the Indian Ocean.
The radiator will be a key part of the space station's solar energy arrays, dissipating the heat generated by the solar panels' electronics.
Heidemarie Stefanyshyn-Piper and Joe Tanner had started the installation of the $372 million (euro292.4 million) solar panel addition to the space station in their first spacewalk, and on Friday were wrapping up the third and final outing of Atlantis' 11-day mission. It was the first construction mission to the space station since the 2003 Columbia disaster.
A minor glitch delayed the spacewalkers Friday morning, but it was fixed after about 45 minutes.
"Oh, that's a beautiful view," Stefanyshyn-Piper said as she floated out of the spacecraft.
Atlantis delivered a 17 1/2-ton truss with two solar panel wings that were unfurled on Thursday and that will eventually provide a quarter of the space station's power. They won't begin generating electricity until the next space mission, though, when the power system is rewired, expected in December.
"You just can't imagine a flight going as well as this one has gone," said lead space station flight director John McCullough. "I couldn't ask for a better start -- a re-start -- to assembly." The astronauts were already well ahead of schedule by Friday. A couple of hours into their spacewalk, Tanner and Stefanyshyn-Piper picked up a science experiment that tested how various materials fare in space and set to work on some installation tasks. They will spend the rest of the roughly 6 1/2 hours on tasks like replacing an antenna.
As they worked on the radiator, Tanner took a moment to appreciate the view.
"Kind of nice up here," he said.
"Didn't get a chance to look around much," Stefanyshyn-Piper said. "At least I can say I've been here."
"Not too many people have," Tanner said.
Their spacewalk was delayed by almost an hour after a surge of electricity caused a circuit breaker to activate. The spacewalking astronauts spent time in a depressurized room to rid their bodies of nitrogen and avoid decompression sickness, and the depressurization pump in that room shut down after the surge. NASA determined the pump did not short and simply restarted it, said spokesman Bill Jeffs.
There also was a temporary glitch with Stefanyshyn-Piper's space suit -- the oxygen pressure dropped momentarily, but it came back up. The astronauts woke up to the rock hit "Hotel California" by the Eagles, a song Tanner's family dedicated to him. "That song reminds me of some great traveling adventures, sort of like this one," Tanner said. "It's gonna be a great day." When Atlantis undocks from the space station on Sunday, the astronauts will fly around it and examine their handiwork, said Mike Suffredini, space station program manager.
This will be the first time since the Columbia broke apart that a crew will be able to do that. Besides the aesthetic benefits, NASA will also be able to check up on areas of the station its engineers do not normally see -- something they aim to do at least once a year. The crew is scheduled to land back on Earth on Wednesday.