Spacewalking astronauts find trouble at Space Station

October 28, 2007

NASA, Houston - Astronauts on a spacewalk on the International Space Station found metal shavings inside a joint that is needed to turn a set of solar power panels.

Astronauts on a spacewalk on the International Space Station found metal shavings inside a joint that is needed to turn a set of solar power panels.

Spacewalker Dan Tani inspected a balky rotary joint on the International Space Station Sunday and found it contained metal filings, which may indicate thermal insulation is in contact with the internal gear system.

"It's quite clear that it's metal-to-metal grating or something, and it's widespread," Tani said.

"Wow," said his spacewalking partner, Scott Parazynski.

The astronaut used tape to dab up some of the shavings. It will be returned to Earth aboard Discovery next week for analysis. NASA is uncertain whether the flecks are metallic, possibly from the aluminum foil lining the thermal covers, or some other material.

Over the past two months, space station flight controllers have been tracking subtle problems with the joint's performance, such as abnormal vibrations and elevated power signatures.

The starboard Solar Alpha Rotary Joint (SARJ), located on the backbone of the station, spins so that the solar wing on that side can track the sun and maximize the generation of electricity. An SARJ on the port side is functioning normally.

Engineers on Earth had hoped Tani would take high-resolution photographs of the shavings for analysis, but neither of two cameras taken on the spacewalk worked.