NASA Schedules Space Walks to Fix ISS Pumps; Orbital Sciences Launch Delayed

The ISS has been operating at partial capacity after a coolant pump malfunctioned last week. NASA has now announced the repair mission: "NASA currently plans for two Expedition 38 astronauts to venture outside the space station Dec. 21, 23, and 25. NASA astronauts Rick Mastracchio and Mike Hopkins will remove a pump module that has a failed valve. They will replace it with an existing spare that is stored on an external stowage platform. The pump is associated with one of the station's two external cooling loops, which circulate ammonia outside the station to keep both internal and external equipment cool. Each of the three spacewalks will begin at 7:10 a.m. and is scheduled to last six and a half hours. NASA TV coverage will begin at 6:15 a.m." NASA TV will be airing a preview of the space walks at 3 p.m. EST. As a result of the coolant pump malfunction and the repairs, NASA has also delayed the launch of Orbital Sciences' cargo resupply mission until at least mid-January.

Re:A question about space walks.

[Trepidity]

So far they seem to be one of the safer parts of spaceflight, in that there have been 204 spacewalkers [wikipedia.org], and none died or suffered serious injuries. Whereas a number of people have died during take-off or reentry. On the other hand, they're typically planned for very carefully and not done that often. And 204 is too small a sample to reliably compare it to the safety of scuba diving, since serious scuba accidents, especially by professionals, are far less common than 1/200 dives.