CAPE CANAVERAL, Fla. — Astronauts took their second spacewalk in two weeks Thursday, taking care of some long overdue radiator work outside the International Space Station.

Commander Jeffrey Williams used a power drill-type tool to fold up a 44-foot-long thermal radiator that’s no longer in use. Spacewoman Kate Rubins floated nearby, making sure Williams was clear of the panel as it slowly retracted, accordion style.

With the radiator closed all the way, they cinched it down in four spots for safekeeping. NASA wants to preserve the radiator as a spare. Outstretched, it was at greater risk of getting hit with space junk.

The radiator was extended in 2012 to help stop a coolant leak. But the leak ended up being elsewhere. Another team of astronauts attempted the radiator retraction late last year, but couldn’t complete the job, so it fell into Williams and Rubins’ gloved hands. The radiator is part of the 250-mile-high lab’s heat-dispelling system.

The two U.S. astronauts installed two new high-definition TV cameras and a camera light, tightened bolts on a solar-panel rotary joint, tied down the brake handles for a rail car, and whipped through a few other chores. As the spacewalk passed the six-hour mark, Mission Control declared victory with all major objectives met, and sent the astronauts back inside. The spacewalk lasted nearly seven hours.

“Great working with you today,” Mission Control radioed.

The same two astronauts installed a new docking port during a spacewalk Aug. 19.

Williams returns to Earth next week. He already holds the NASA record for most accumulated time in orbit; his tally will reach 534 days over four missions by the time he’s back on Earth.

Mission Control, meanwhile, kept news about a devastating launch pad explosion at Cape Canaveral from the two spacewalkers while they were outside.

SpaceX was fueling its unmanned Falcon rocket for a test engine firing when a fireball erupted, an hour into the spacewalk. Both the rocket and its payload — an Israeli communications satellite — were destroyed. The launch had been scheduled for Saturday.

SpaceX is one of two companies supplying the space station for NASA. It’s also working on a crew capsule to ferry station U.S. astronauts; that first flight was supposed to come as early as next year. The newly installed docking port is meant for the SpaceX crew Dragon, as well as Boeing’s Starliner capsule, also still in development.


Online:

NASA: http://www.nasa.gov/mission_pages/station/main/index.html