International Space Station mission managers decided Thursday to wait until Saturday for the first of two spacewalks to repair the orbiting laboratory’s cooling system, which was hobbled by an electrical short in an external pump module assembly on July 31.
The first of the six-and-a-half to seven hour spacewalks by NASA astronauts Doug Wheelock and Tracy Caldwell Dyson is scheduled to get under way on Saturday at 6:55 a.m., EDT. If all goes well, the pair will complete their repair work on Aug. 11 with a spacewalk of similar duration and also starting at 6:55 a.m., EDT.
Previously, the spacewalks were scheduled for Friday and Monday. However, NASA’s Mission Control decided ground teams needed more time to plan the outings. Initially, the spacewalks were set for Thursday and Saturday.
The NASA astronauts plan to replace the 780 pound pump module on the right side of the station’s 357-foot-long solar power truss with a $3.9 million spare already stowed on the U. S. Quest airlock. The task will require them to break connections and re-mate five electrical cables and four fluid lines used to circulate ammonia through outstretched radiators on the truss.
The space station’s mission management team plans to meet Friday to formally approve the latest repair strategy.