NASA ISS On-Orbit Status 1 August 2010 (early edition)

"After losing one cooling system pump (of two), ISS is currently stable, although thermally on single string (no redundancy). Last night (at 7:48pm EDT) RPC1 (Remote Power Controller 1) in RPCM (RPC Module) S11A_D tripped open, powering off the Loop A ammonia pump of the S1 ETCS (External Thermal Control System), resulting in the loss of one half of the cooling to ISS. This required a number of powerdowns (i.e., turning off selected systems for thermal protection), including redundant power to four CQs (Crew Quarters), three in Node-2, one in Kibo JPM, with both fans in each CQ remaining functional but zero fault-tolerant (crew is still Go for CQ use). Due to loss of heater power, MBS (Mobile Base System), SSRMS (Space Station Remote Manipulator System), and SPDM (Special Purpose Dexterous Manipulator) are currently zero fault-tolerant."

International Space Station in Stable Configuration After Loss of Cooling Loop

"The flight control and management teams today approved a preliminary plan to replace a planned spacewalk Thursday by Expedition 24 crewmembers Doug Wheelock and Tracy Caldwell Dyson with at least two spacewalks to swap out the failed Pump Module that resides on the station's S1 truss. There are two spare Pump Modules on stowage platforms on the station's truss. The replacement module under consideration for replacement resides on External Stowage Platform 2, which is adjacent to the Quest airlock. The crew is being informed that replanning for alternate spacewalk activity is underway."

Keith's note: Of course, YouTube has the solution to this problem ...