Updated NASA technicians have managed to restore communications with the International Space Station (ISS) after the failure of three command and control computers on board the craft.
One machine is now fixed and ground controllers hope the mission can now carry on as normal.
Life support systems and other automatic functions are not affected by the problem, which may be software related, and astronauts are in no immediate danger.
Contact with the space station was being maintained through the shuttle Endeavour, which is delivering a robot arm to the station. This was fortunate because if Endeavour wasn't docked with the station, NASA would have been left unable to communicate with the space crew.
The problems in space began shortly after the astronauts went to bed on Tuesday night, when the station's main command and control computer, one of three identical computers on board, failed.
Attempts to switch over to a backup computer failed when crew were unable to get it to talk to the station's systems management database.
A reset seemed of the machines seemed to work at first but the system crashed again after only a few minutes. Attempt to switch over to a third computer also failed.
After the first computer was reset, technicians in Houston were able to remotely turn off a light in the station's Destiny laboratory but they weren't able to repeat the task.
This meant NASA had to go back to the drawing board in diagnosing the source of the problem.
On its ISS mission status page NASA has posted an explanation of its troubleshooting thus far.
A notice, posted late last night US time, said: "Overnight the space station flight control team will attempt to reset the computers by commanding them from the 'primary' to 'standby' mode in an effort to clear any software interaction that might be causing the problems,"
NASA hasn't said what the problem machines are but all a strong body of evidence points to IBM Thinkpads featuring older Intel processors, when the project began around two years ago these machines used 486 chips.
Back in February we obtained exclusive pictures on a crashed IBM Thinkpad on board the space station. Subsequent emails from our readers revealed these machines were involved in far more than playing space invaders. It seems the laptops were running most of the main functions on board the station, including the communications functions that have failed.
The failure on board the space station is surprising because NASA commonly uses tried and tested 'archaic' technology where the robustness of newer kit might be questionable
Despite this there have been well-sourced reports which suggest that astronauts have been unable to pick up email and that the Ethernet network on board the craft was unreliable. Apparently it's not just the crew of Apollo 13 who've had reason to say "Houston, we have a problem"... ®
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