The astronaut Suni Williams will today become the longest-serving woman in orbit. But in a day of high drama on board the International Space Station yesterday, she may have wondered whether her six-month odyssey was about to meet a sticky end.

An unprecedented computer crash on board the £50 billion laboratory, which flies more than 200 miles above Earth, left Ms Williams, her two Russian crewmates and scores of engineers on opposite sides of the world scrambling for answers as critical life-support and navigation systems went into meltdown.

As the ISS switched to back-up oxygen supplies, the space shuttle Atlantis — which is currently docked there — fired its thrusters to keep the station correctly positioned, while mission managers in Moscow and Houston held talks.

An all-night recovery effort by ground controllers resulted in the partial restoration of computer functions, allowing Ms Williams and her colleagues to head for their sleeping quarters to snatch some rest.

Four minutes after they had wriggled into their sleeping bags, the fire alarm went off, forcing them back into emergency mode.

“There’s always something exciting every day. That’s why we do this,” said Holly Ridings, Nasa’s space station flight director, as managers declared the fire bell a false alarm and the crew mopped their brows.

Efforts to bring the failed technical systems fully back to life continued, with experts at the Russian space agency, Roskosmos, expressing confidence that a solution was in sight. However Bill Gerstenmaier, Nasa’s associate administrator of spaceflight operation, admitted last night that while some of the computers had come back online for a short while, they had subsequently crashed again and technical experts were still puzzling over the problem.

“We are still struggling to understand what the real problem is here . . . we’ve got a challenge, we’ll go figure out some clever ways to get this behind us,” he said.

As a fallback, Nasa — which shares responsibility for the ISS — instructed its seven astronauts on board Atlantis to save electricity by dimming their cabin lights, switching off laptop computers and unplugging printers.

The measures will conserve enough power to keep Atlantis docked for an extra 18 hours beyond its scheduled departure time next Wednesday, if required, to maintain the station’s steering and allow extra time for the recovery effort.

Though the scene may not have quite matched that portrayed in Stanley Kubrick’s film 2001: A Space Odyssey — in which a spacecraft computer HAL suffered the cyber-equivalent of a nervous breakdown and turned on its crew, with fatal consequences — it was the first time since the ISS became operational seven years ago that its technology has failed so spectacularly.

In the worst-case scenario, the station will be evacuated next week if the problems persist, leaving it unmanned for the first time in its history, though officials consider that unlikely.

“We have the option to depart . . . Clearly we need to get the computers up and running before the shuttle leaves,” said Mike Suffredini, Nasa’s space station manager.

The problems could make today’s celebrations for Ms Williams an uneasy affair. She will break the 188-day record set in 1996 by her Nasa collague, Shannon Lucid, for the longest spaceflight by a woman.

Ms Williams is accustomed to sticky situations. After requesting a tube of wasabi, a fiery condiment, to be sent up in March, she accidentally sprayed it across the ceiling when she opened it in the low-pressure atmosphere of the ISS.

She will act as a back-up today as two colleagues, Jim Reilly and Danny Olivas, venture outside on a six-hour spacewalk to expand the space station’s solar power systems and mend a tear in the shuttle’s thermal blanket.

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