False alarms at space station

[Guest Glenn]

Source: news.com.au

 

TWO US astronauts spending the night in an airlock aboard the International Space Station had to call off their outing after a software glitch sent off a series of false alarms.

 

Camping out in the slightly depressurised airlock was intended to test a new technique that would shave hours off the time it takes to prepare for a spacewalk.

 

Astronauts Bill McArthur and Jeffrey Williams retired to the US airlock module last night for what was expected to be an undisturbed night.

 

But loud alarms rang out twice during the night due to a software glitch that falsely detected low levels of carbon dioxide. NASA cancelled the camp out at 12.43am EDT (2.43pm AEST), said spokesman Kyle Herring.

 

Before a spacewalk, astronauts must breathe pure oxygen to purge nitrogen from their bloodstreams. The nitrogen could cause a dangerous condition known as "the bends", which commonly afflicts divers who surface too quickly.

 

Lowering the airlock's ambient air pressure cuts the amount of time astronauts need to breathe pure oxygen, reducing preparation time for spacewalks.

 

Undaunted by the interrupted night's sleep, McArthur told ground controllers he and Williams had fun nonetheless.

 

"We enjoyed our little adventure last night. It's a good chance to get into some of the guts of the airlock," he said early today.

 

McArthur, the station's current commander, and his crewmate aboard the orbiting outpost, cosmonaut Valery Tokarev, are scheduled to return to Earth this weekend after a six-month stay in space.

 

Williams and the incoming commander, cosmonaut Pavel Vinogradov, arrived at the station on Sunday to begin their mission. Visiting Brazilian astronaut Marcos Pontes was aboard the crew's Soyuz capsule as well and will be returning to Earth with McArthur and Tokarev.