Space station may need emergency spacewalk if software patch fails ( video)

NASA engineers appear to have found a way to restore a balky coolant pump on the International Space Station that may allow a station resupply mission to launch this week, as planned. The alternative is to delay the launch to allow two ISS crew members to conduct two or three emergency spacewalks starting this weekend to replace the faulty pump. Spare pumps are stored on the space station's truss – scaffolding the length of a football field. The truss supports the station's solar panels, radiators for station cooling, and other utilities, including two external cooling loops that transfer heat to the radiators. The cooling-system malfunction on the space station occurred Dec. 11.