Space station computers up and running

Russian cosmonauts on Saturdaybegan turning back on some crucial systems that had been shut down more than four days ago when a computer system on the Russian side of the international space station crashed.

The first system turned on was a machine that scrubs carbon dioxide from the air inside the space station.

Just a day earlier, Fyodor Yurchikhin and Oleg Kotov were able to get four of six processors on two computers working again by using a cable to bypass a circuit board.

It took four days to restore the capability of the computers.

"In the last 24 hours, we've had a lot of successes," flight director Holly Ridings said Saturday morning.

The computers on the Russian side provide oxygen and maintain the space station's correct position in orbit, allowing it to point its solar arrays at the sun for power and shift orientation to avoid occasional large debris that comes flying through space.

The computer problem had raised the possibility the space station's three-person crew might have to abandon the outpost. NASA officials rejected such a scenario.

"We feel like the computers are stable and back to normal," said Mike Suffredini, NASA's manager of the space station program.

The cosmonauts may use another jumper cableSaturday to get the last two failed processors on the computers working, Ridings said.

Suffredini, however, said Friday night that engineers don't expect the other two processors to come back online. They will be replaced.

Engineers were still trying to determine what prompted the power switch to cause the computers to fail, Suffredini said.

Early Saturday, U.S. astronaut Sunita Williams set the record for the longest single space flight of any woman, passing astronaut Shannon Lucid's record of 188 days.

The seven astronauts visiting on space shuttle Atlantis and the three space station crew members planned to spend most ofthe daymoving supplies and trash back and forth between the vehicles, and preparing for the mission's fourth spacewalk on Sunday.

For now, Atlantis is set to land at Cape Canaveral, Fla., on Thursday. But Suffredini said NASA officials were still deciding whether to keep the shuttle at the station an extra day because of the computer problem.

During the failure, the shuttle's thrusters helped control the station's position. Some of Atlantis's lights, computers and cameras were turned off to save energy in case the shuttle had to stay an extra day.

Oxygen depletion not a problem

NASA officials said the crew was never in danger of running out of oxygen, power or essentials.

The 11-day space station construction mission had already been extended by two days so a rip in the shuttle's thermal material could be fixed.

The failed computers were the latest technical glitch for the half-built, $100- billion USoutpost. A Russian oxygen machine and gyroscopes, which also control orientation, have previously failed.

The computer problem renewed criticism of the space station, which has been called an ill-conceived venture, as well as criticism of President George W. Bush's Vision for Space Exploration, which calls for finishing the space station in three years, grounding the space shuttles in 2010 and building next-generation vehicles to go to the moon and Mars.

"We're learning a great deal from the space station, and one of things we may be learning is we shouldn't have built this particular one," said Howard McCurdy, a space public policy expert at American University.

Two spacewalking Atlantis astronauts accomplished another critical task Friday: repairing a torn thermal blanket that helps protect the shuttle from heat on its return flight to Earth.