The primary computer aboard the International Space Station continued to work well through the night, but flight controllers continued to encounter difficulties recovering the station's backup computers.
The station's two backup command and control computers remain off line. Attempts overnight to reload software in one of the computers were not successful. Analysts on the ground have uncovered an error in the software load that they believe may have been the source of the problem. Further efforts to reload software into the backup computers are expected to resume later this morning.
Even if backup computers are not yet on line, the crew may be given a go today to use the station's robotic arm in an abbreviated maneuver to hand a carrier pallet to Endeavour's arm so that it may be stowed aboard the shuttle for a return to Earth. If so, the joint robotic activities would begin no earlier than 8 a.m. to allow time for managers to thoroughly evaluate the plan.
Meanwhile, the crews are using the shuttle's robotic arm and cameras and the station's cameras to calibrate the Space Vision System, a precision alignment aid for operators of the robotic arm, and gather information that will help prepare for the next shuttle mission to visit the station. On that flight, planned for launch in June, the Space Vision System will be a key aid for using the station arm to attach a new airlock to the station. The crew also is continuing the transfer of equipment from the shuttle to the station during the day, and may work on some station maintenance tasks. A joint crew press conference, during which the 10 astronauts and cosmonauts will field questions from U.S., Canadian and European media, is planned at 1:41 p.m. CDT.
Shortly after Endeavour's crew awoke today, Mission Control reported to them the successful launch of a replacement Soyuz spacecraft bound for the station from the Baikonur Cosmodrome in Kazakstan. The Soyuz, with a taxi crew of Commander Talgat A. Musabaev, Flight Engineer Yuri M. Baturin and American businessman Dennis Tito, will replace the Soyuz spacecraft now attached to the station, which is nearing the end of its lifetime as a station emergency "lifeboat." The new Soyuz is tentatively planned to dock with the station at 3:05 a.m. CDT Monday, however the Soyuz docking plans will be delayed if a decision is made to further extend Endeavour's stay at the station.
The shuttle crew was awakened today to the song "Dangerous," sung by C'est Cheese, played for Canadian Astronaut Chris Hadfield at the request of his wife. The station and shuttle are in an orbit of about 250 by 235 statute miles. The next mission status report will be issued later today as events warrant.
- end -