-- An accident Tuesday aboard the International Space Station further reduced the station's power capabilities and heightened uncertainty about NASA's ability to finish building the $100 billion complex.
Astronauts on the station were unfurling the solar panel Tuesday when it ripped. The crew halted the opening of the panel, but not before the tear measured 2½ feet. The 115-foot-panel was about 80% to 90% extended.
The incident only added to the station's power-generation woes. On a spacewalk Sunday, an astronaut found metallic debris inside a huge wheel that points a different set of solar panels at the sun. The wheel has been locked in place to avoid permanent damage to the mechanism, cutting the station's power supply.
Neither the station nor its three-person crew is in immediate danger, but the twin problems will further complicate NASA's goal of finishing the station. Construction of the orbital laboratory faces a rigid deadline of 2010. That's the year the space shuttle is scheduled to retire, and no other space vehicle can lift the station's components into orbit.
The rip in the solar panel could keep a European laboratory from being added to the station in December as planned, station manager Michael Suffredini said Tuesday.
Just one day earlier, he had acknowledged that the malfunction of the rotating wheel meant the station could not make enough power to support a Japanese scientific facility scheduled to be added to the station in April.
The newly ripped solar panel "just adds to the (wheel) problem we were busy getting through," Suffredini said. "This will take time and needs to be worked."
The station's woes are so urgent and serious that Suffredini said he might ask the crew of shuttle Discovery, which is now visiting the station, to extend a stay that has already been lengthened once. NASA decided Monday to add a day onto the shuttle's station visit so the crew could help troubleshoot the debris-jammed wheel.
The station's solar panels, despite the problems, are producing enough electricity to keep the structure alive. The torn panel is generating 97% of the electricity NASA wanted it to make, and the solar panels that are frozen in place because of the broken wheel also are generating power.
Even so, the station isn't producing enough power to accommodate the rooms that NASA planned to add over the next six months, and the torn solar panel may not have the strength to withstand the strains it will face in orbit, Suffredini said.
NASA managers had decided Monday to abandon a spacewalk to test methods of repairing the shuttle's heat shield. Instead, spacewalking astronauts were asked to inspect the jammed wheel Thursday to help determine the sources of the debris and extent of the damage. Suffredini said that spacewalk may also include study of the rip.
Station commander Peggy Whitson told Mission Control that the sun made it difficult to see the rip, preventing the astronauts from halting their work immediately.
"No worries, Peggy," astronaut Kevin Ford replied from Mission Control. "That's just the way it happens."