Spacewalkers to inspect station for meteoroid strike

Commander Peggy Whitson enters the Qwest airlock at the end of her seven-hour spacewalk from the International Space Station with fellow spacewalker Dan Tani (not pictured) in this image from NASA TV November 24, 2007. Whitson and Tani, who are on the International Space Station will make a spacewalk next week to find out if a micro-meteorite strike damaged a critical part of the outpost's power system, officials said on Thursday.

CAPE CANAVERAL, Florida (Reuters) - Two astronauts on the International Space Station will make a spacewalk next week to find out if a micrometeoroid strike damaged a critical part of the outpost's power system, officials said on Thursday.

The station is not in any danger and is still producing enough power to support the arrival of a Russian cargo ship this month, said station deputy program manager Kirk Shireman.

Analysis is under way to determine if changes need to be made to NASA's plan to launch the space shuttle Atlantis in January with Europe's Columbus science module on board.

That flight, originally planned for last week, was postponed when sensors in the shuttle's fuel tank failed during two launch attempts.

NASA had said it would try again no earlier than January 2. But on it said it had reset the target date to January 10 to give workers more time with their families during the holidays.

Shireman said the power problem would probably not affect plans to attach Columbus to the station next month. But flights of Japanese modules in February and April could be affected.

Without repairs, "we know we can't go too much farther," he said.

Station commander Peggy Whitson and flight engineer Dan Tani are scheduled for a 6.5-hour spacewalk on Tuesday to inspect two joints needed to position the station's right-side solar panels toward the sun.

The primary joint, which rotates the panels 360 degrees, was locked in place by spacewalking astronauts in October.

A problem with a second joint, which lets the panels pivot while the primary joint is locked, surfaced on December 8. "It makes power generation much more difficult," Shireman said.

Because several independent pieces of equipment were simultaneously affected, engineers suspect a micrometeoroid strike may be to blame.

They also theorized a piece of debris may have worked itself free and floated into an area that shorted out electrical components.

Spare parts to fix the second joint are on board the station, though if the problem is with the device's cables a repair would have to wait until supplies arrive on the next cargo ship or aboard the shuttle, Shireman said.

"This (spacewalk) is a fact-finding mission," he said. "It is hoped that something the crew sees can help us narrow down the problem."

(Editing by Jane Sutton)