Two U.S. shuttle astronauts bounced at the end of a long pole in space Saturday as they circled the earth docked at the International Space Station. They were testing whether the boom is suitable as a platform from which to make shuttle repairs in orbit.
Like a circus highwire act, astronauts Mike Fossum and Piers Sellers stood 340 kilometers above Earth, bouncing, twisting, and bending forward and backward at the end of the 30 meter boom.
The boom is an extension of the shuttle's original robot arm. It was designed to hold a camera to inspect potential damage to the fragile heat shield on the shuttle's underside. NASA developed the orbital inspection procedure as the result of the disintegration of the shuttle "Columbia," whose heat shield was punctured by hard insulating foam that had broken away from the external fuel tank during launch.
NASA wanted to know if the spindly boom is stable enough to hold people in case human inspection and emergency orbital repairs are necessary beneath the shuttle.
Fossum gave his opinion to U.S. Mission Control in Houston. "The boom's motion itself if smooth, very smooth," he said.
The astronauts' other task during their seven hour outing was to replace a cable to the space station's rail car, which positions the outpost's mechanical arm during construction. The cable was accidentally severed last year by a cable cutter, so the two crewmen also locked the cutter to prevent a recurrence.
Work was not the only thing on their mind. Before floating out of the hatch into space, Sellers asked mission control what countries will face each other in Sunday's World Cup football championship. They launched Tuesday before the finalists were known.
[Sellers] "We never found out. We've been too busy. Maybe Houston knows."
[Mission Control] "It's France and Italy. They are still in it. The final game is tomorrow."
[Sellers] "Oh, okay. Thanks. [We've] got to pick a side."
This was Sellers' fourth spacewalk, but the first for Fossum. Like all novices, he marveled at the view below and picked out several geographical points, including South America's Andes mountains, Ireland, England, and the Caspian Sea. "I'm in a dream," he said. "Nobody wake me up!"
He and Sellers will make take two more spacewalks during the shuttle's two-week visit to the space station. It is the first shuttle mission in almost one year. One purpose is to replace space station supplies and deliver German astronaut Thomas Reiter as a third crewmember. But it is also a mission to test shuttle repair techniques and changes NASA has made to the orbiter's external tank to ensure it never again sheds pieces of foam large enough to endanger a shuttle.