Monday, August 9, 2010

A faulty ammonia line fitting delayed repairs to a cooling pump on the International Space Station Saturday during an eight-hour spacewalk.

During the spacewalk, astronauts Doug Wheelock and Tracy Caldwell Dyson were to repair a faulty cooling system, which failed on July 31. The faulty cooling unit was to be swapped with a new one that was previously in storage to solve the problem; however, an ammonia leak in the final line to be disconnected from the unit halted attempts for a repair.

Upon discovering the problem, the astronauts were instructed to reconnect the line and install a positioning device to maintain the proper pressure on the line.

Upon completing the spacewalk, Wheelock and Dyson spent additional time in the airlock to get rid of any ammonia particles that may have attached themselves to their spacesuits.

NASA officials are analyzing possible solutions to the issue to attempt during a planned spacewalk Wednesday. Wednesday’s spacewalk was previously intended to be second in the series to repair the cooling system by reattaching fluid and electrical lines.

Before Saturday’s spacewalk, NASA officials projected that up to three spacewalks may be needed to repair the cooling system.

Most of the space station’s non-critical scientific components have been temporarily shut-down in order to reduce heat generation with only one cooling loop available to the station.

NASA reports that the station’s crew, three Russians and three Americans, are not in any danger; however, it is in the best interests of the crew to restore systems to nominal condition as soon as possible.

The eight-hour spacewalk is reportedly the longest ISS-based spacewalk, and the sixth longest in the history of human spaceflight.