CAPE CANAVERAL — Two astronauts cut short their space walk and hurried back to the safety of the International Space Station on Wednesday after a suit problem resulted in rising carbon dioxide levels for one of the men.
Five hours into the space walk, Mission Control notified the crew that the canister for removing carbon dioxide from Christopher Cassidy's suit did not seem to be working properly. Flight controllers wanted him back inside quickly. That meant fellow spacewalker David Wolf had to go back in early, too.
Their battery replacement work outside the space station was left unfinished. Only two of four new batteries ended up being installed.
Cassidy immediately headed for the hatch. He waited there for Wolf, who was farther out on the space station. Their work site, along the framework that holds the huge solar wings, was more than 150 feet from the hatch.
"I'm just going to sit here and I'm going to wait for Dave and enjoy the view," Cassidy said.
Both men were back inside and the space walk was over a half-hour after Mission Control's initial call to cut it short. It ended up lasting six hours, a half-hour shorter than planned.
It was the third space walk in five days for shuttle Endeavour's crew. Two more are planned, on Friday and Monday. More battery work had been planned for Friday, with a total of six new station batteries to be installed by mission's end.
Mission Control said the unfinished battery work from Wednesday would be squeezed into one of the next space walks.
The nickel-hydrogen batteries store power collected by the space station's solar wings. The new batteries cost $3.6 million apiece.
The shuttle, in orbit for a week now, will undock from the space station on Tuesday. Landing is set for July 31.