Posted: Thu, Apr 15, 2010, 8:14 AM ET (1214 GMT)
NASA managers decided late Wednesday that they would not perform an additional spacewalk on the current shuttle mission to the International Space Station in order to repair a faulty valve. NASA had considered adding the spacewalk after encountering a stuck valve in a nitrogen pressurization system that is part of the cooling system whose ammonia tank was replaced in a series of spacewalks during the mission. Engineers decided that the problem did not pose an immediate risk for the station, allowing them more time to either troubleshoot the problem or perform an EVA after the shuttle leaves to replace the nitrogen tank.
