boston.com your connection to The Boston Globe

NASA tries to fix solar array on station

Half-retracted wing won't fold up

CAPE CANAVERAL, Fla. -- NASA asked an astronaut aboard the international space station to exercise vigorously yesterday, hoping the rapid movement would jostle a half-retracted solar wing that refuses to fold up properly.

German astronaut Thomas Reiter of the European Space Agency was told to do 30 seconds of robust exercise on a bungee-bar machine in an attempt to vibrate wires on the 115-foot solar array and prevent an unplanned, fourth spacewalk.

Reiter tried several times, but his exercise did not change the solar array.

"I'm very sorry to hear that," said Reiter, who has been at the space station since July. "I was training for it for a half-year."

Mission Control radioed back, "We'll give you a silver medal for that."

Earlier in the day, flight controllers jiggled the solar array 10 degrees to either side by remote control to try to relieve tension in a wire system that is preventing it from folding up like an accordion, as designed. That also did not have the desired effect.

Flight controllers thought Reiter's workout might fix the problem based on previous experience. NASA officials recalled a time the space agency saw an array shaking and found the cause was astronaut Leroy Chiao working the exercise device hard.

Space station crew members are required to exercise two hours a day to prevent loss of muscle mass.

"If you think of the station as kind of a long beam . . . If you're at one end putting a force into it, you'll get some vibration going on," Chiao told the Associated Press yesterday. He lived aboard the space station from October 2004 to April 2005.

The solar wing was part of an interim power system. A primary goal of shuttle Discovery's seven-day visit to the space station was to rewire the lab oratory and hook a new set of solar wings onto the permanent electricity grid.

The new panels rotate with the movement of the sun to maximize the amount of solar energy produced, but in order for the new panels to spin, the old panel had to be retracted.

While it was folded far enough to give clearance to the new panels, the old one got stuck after retracting halfway. NASA had wanted it to retract fully.

SEARCH THE ARCHIVES
 
Today (free)
Yesterday (free)
Past 30 days
Last 12 months
 Advanced search / Historic Archives