“We think we are taking out two clean suits to the best of our knowledge,” said Dina Contella, who will be the NASA ISS flight director during the spacewalks. “(But) we can’t rule out that we would have water in the suits again.”
Mastracchio and Hopkins regularly conduct “feel” tests for water in their helmets as part of a change in procedures.
The cooling system difficulties surfaced Dec. 11, when a flow control valve in Loop A of the station’s dual loop external cooling system faltered. Loop A and B circulate ammonia coolant through external radiators to remove heat from the station’s electronics, including those associated with life support and research hardware.
The loss of thermal control prompted the shutdown of noncritical systems in the station’s European and Japanese research modules as well as the U.S. Harmony node.
Earlier this week, NASA flight control teams achieved limited success in restoring a backup Loop A cooling capability using an isolation valve and software patches.
The difficulties also forced NASA to reschedule the launch of Orbital Science Corp.’s ORB-1 resupply mission to the ISS from Dec. 19 to no earlier than Jan. 13. The launch of the Antares rocket and Cygnus cargo capsule from Virginia’s Eastern Shore will mark the first under an eight-flight, $1.9 billion Commercial Resupply Services contract between Orbital and NASA.
The flow control valve is located within the pump module. Three spare pump modules are stowed outside the ISS, with the replacement cradled on the starboard truss in the External Stowage Platform 3.
Mastracchio, 53, is a three-flight, six-spacewalk veteran who was selected by NASA for astronaut training in 1996. Hopkins, 44, is a U.S. Air Force colonel who is flying for the first time, following his selection by NASA for astronaut training in 2009. Mastracchio and Hopkins reached the ISS for six-month assignments on Nov. 6 and Sept. 25 respectively.
Japanese astronaut Koichi Wakata, 50, a three-flight veteran, will serve as the operator of the Canadian robot arm during the spacewalks. The 58-ft.-long robot arm will allow the spacewalkers to be moved around outside the station. cherry picker style. Selected for astronaut training in 1992, he arrived at the station on Nov. 6.