Astronauts Find Problem On Space Station
Spacewalking astronauts today discovered metal shavings all through a rotary joint used to position solar panels. This is not good, but not an emergency at this time. Samples of the shavings were taken for later analysis and NASA engineers are trying to figure out the best fix for the problem.
The rotary joint, 10 feet in diameter, has experienced intermittent vibrations and power spikes for nearly two months. Space station managers were hoping a thermal cover or bolt might be hanging up the mechanism, which would have been relatively easy to fix, and were disheartened when Daniel Tani radioed down that metal shavings were everywhere.
"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 shavings resembled small flakes and were clinging to the joint as if to a magnet, Tani said. "It looks like a dusty table that you'd want to dust at home," he called down.
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 actually metallic, possibly from the aluminum foil lining the thermal covers, or some other material.
This rotary joint, launched and installed just four months ago, controls the huge solar panel wings on the right side of the space station, to make sure they're facing the sun. The joint for the left solar wings is working fine.
The rotary joint will remain in a parked position as much as possible until the problem is solved, said Mike Suffredini, NASA's space station program manager. Flight controllers were trying to determine whether any more inspections or even repairs will be needed in the coming week, or whether they can continue to work around the problem following Discovery's departure.
Other tasks on the spacewalk went well.
By NortonPete, Sunday, 28 October , 2007 @ 2:45 pm
Not good. If it were just pieces from the aluminum foil lining it would also be on the other joint. The bearing is shot, now it only moves at extremely low rpm so depending on the thickness of the raceway it might sit there grinding away for years. I’ve seen low rpm bronze bearings with enough slap to put a tooth pick in and no problem. Hopefully.
But it appears to be bad workmanship.