By Ed Stoddard HOUSTON, June 16 (Reuters) - Russian cosmonauts aboard the International Space Station were trying on Saturday to kick-start components of a critical computer system that were still down, but most parts were up and running, raising hopes they would not crash again. "They will try and route the current around a suspect switch. They were given the command to do so this morning," a NASA spokesman said. Four of the six boxes or "lanes" that comprise the computer system were working, easing worries of ground controllers. "In the last 24 hours, we've had a lot of successes. All four of them (the revived lanes) are talking to each other which is a huge improvement from yesterday," said Station flight director Holly Ridings. An unprecedented failure of the computers in the Russian segment of the station on Wednesday raised alarms that the manned space outpost might have to be temporarily evacuated. Among other crucial functions, the systems control the station's positioning in space so it can draw power from the sun, maintain proper temperature and position antennas for communicating with ground controllers. Visiting NASA astronauts from the space shuttle Atlantis were preparing for the mission's fourth spacewalk scheduled to take place on Sunday. Their main task will involve removing restraints on a mechanism that allows the station's new solar array wings to track the sun. Spacewalking astronauts on Friday repaired worrying insulation damage to Atlantis that was incurred during its flight into orbit last week. Managers said repairing the damage would protect the shuttle's underlying structure from weakening during the scorching plunge through the atmosphere on the shuttle's scheduled return to Earth next week. A mission milestone was reached at 1:47 a.m. EDT (0547 GMT) on Saturday when Sunita "Suni" Williams passed 188 days and four hours in space, setting the record for the longest-duration single spaceflight by a woman. Williams traveled to the space station on the previous shuttle journey in December and is due to return with Atlantis when its current mission wraps up. "You are setting a record every second you are up there," Mission Control in Houston told her on Saturday. "I'm just in the right place at the right time," was her reply. NASA said the previous record was set by American Shannon Lucid on a mission to the Russian Mir space station and had stood since 1996. (Additional reporting Irene Klotz in Cape Canaveral)
