Spacewalkers prepare for solar panel fix (Reuters)

17.12.2006 06:05 Space - Source: Yahoo space

LOS ANGELES (Reuters) - Spacewalkers aboard the

International Space Station prepared on Sunday for an unplanned, fourth outing to fix a stuck solar array, while other crew members finish transferring cargo brought up by the shuttle Discovery.

Mission controllers said they were "very confident" the spacewalk on Monday by shuttle astronauts Robert Curbeam and Christer Fuglesang would get the job done.

The jammed solar wing panel has been an unexpected blot on an otherwise successful and complex mission to rewire the space station to ready it for the addition next year of new laboratories built by Europe and Japan.

The crew retracted the 110-foot (33 meter) wing so that a new set of solar panels could rotate and track the sun, but the half-open panel posed problems for future missions.

NASA sent Curbeam and first-time spacewalker Sunita Williams to inspect the panel after they finished rewiring the space station. They spent part of their 7-1/2 hour spacewalk shaking the array to free grommets hanging up on wires that guide the solar blanket into a storage box at its base.

The ground crew retracted about two-thirds of it before the astronauts ran out of time on the spacewalk.

The array must be stowed completely so it can be moved to a new location on the space station during a later mission.

John Curry, lead flight director for the space station, said NASA was already applying lessons learned to a shuttle mission scheduled for March, in which the other half of the balky solar array must be retracted.

SHAKE SHAKE SHAKE

The astronauts now plan to prepare tools to be used to loosen the grommets if shaking doesn't work. They will wrap the tools in a synthetic tape that insulates them from electrical current from the charged panels.

The ground crew was moving a robotic arm into place in case it is needed to lift spacewalkers close to the panel.

"We will start with the shaking method or use the arm as a backup," said Tricia Mack, lead spacewalk officer. "I personally thing shaking looked pretty good today."

Mack said ground controllers hoped to get the fix done in less than 6-1/2 hours but were prepared to go longer. The spacewalk would be Curbeam's fourth -- a record number of outings for a single mission, Mack said.

The astronauts were expected on Sunday to finish transferring cargo and supplies to the space station, and loading cargo on Discovery for the trip back to Earth.

The fourth spacewalk will delay Discovery's homecoming one day until Friday. Flight directors plan to put all three shuttle landing sites in Florida, California and New Mexico on alert to increase the chances of a landing that day.