Computers still down aboard International Space Station

Time is growing ever more critical for NASA in its uphill battle against a rash of computer failures aboard the International Space Station as a departure deadline for the space shuttle Endeavour neared. Endeavour's deadline had little to do with millionaire space tourist Dennis Tito, expected to arrive at the station aboard a Soyuz capsule with a crew of Russians on either Sunday or Monday. It had everything to do with the shuttle's own limited supplies of electric power, oxygen and fuel. NASA will keep some in reserve in case bad weather on Earth delays a landing but wants the shuttle on the ground by Wednesday. The space station was in the same posture on Saturday that it had been in for days, with one of three command computers sometimes working, sometimes not, and two backup computers down and out. Several associated systems were also affected. NASA has been using Endeavour as a kind of guardian, able to substitute its systems for certain ones aboard the space station - especially communications - since the series of computer failures began on Tuesday. Since NASA still did not know what caused the series of computer crashes, ground controllers were very tentative about issuing commands that might bring the whole system down again. Mission Control's directives to the astronauts were punctuated with phrases like "Please don't touch anything" or "Please don't take any action," according to Reuters. NASA said it hoped the station was back to normal by the time Endeavour left but was not sure what to do if it was not. It is "something we haven't pressed really hard on yet," said Wayne Hale, a mission operations manager at Mission Control. "We want to have a near normal set of conditions before we leave."