Article Posted on : - Jul 27, 2009

In this photo provided by NASA, almost lost to the vision among tons of space hardware, astronauts Christopher Cassidy, partially in frame at upper left, and Tom Marshburn, mission specialists for STS-127, share duties on the fourth spacewalk of Endeavour's current mission and its crew's joint activities with the space station. Eleven astronauts and cosmonauts remained inside the international space station and the shuttle to which it was docked, while the two continued work on the orbital outpost, Friday, July 24, 2009. Image Credit: NASA

CAPE CANAVERAL (PTI): A space station air purifier was working again Sunday after it shut down at the worst possible time, when the shuttle Endeavour's crew was still visiting and had swollen the on-board crowd to a record 13.

The repair by flight controllers, albeit temporary, came as a great relief to NASA.

Even if the carbon dioxide-removal system had remained broken, shuttle Endeavour would not have had to undock early from the international space station, said flight director Brian Smith. But the system needs to work to support six station residents over the long term, he said.

The machine for cleansing the station atmosphere, on the US side of the sprawling outpost, failed yesterday when it got too hot and tripped a circuit breaker.

Flight controllers managed to get the unit up and running again 8 hours later in manual mode. That means extra people are needed in Mission Control - six each day - to handle the approximately 50 computer commands that need to be sent up every few hours.

Normally, the system runs automatically. Smith said engineers hopefully will come up with a software solution soon to have the system back in automatic.

An air-cleansing system on the Russian side of the station is working fine. In addition, the station has about three weeks' worth of canisters for removing the carbon dioxide exhaled by six crew members. The astronauts would have relied on those canisters to prevent an early undocking of Endeavour, if the U.S. carbon-dioxide removal machine not been coaxed back into operation.

The shuttle and its crew of seven will depart Tuesday, as originally planned.

Before leaving, the shuttle astronauts have their fifth and final spacewalk to perform.

Liftoff is now targeted for Aug. 25 at the earliest.