After an exhaustive effort to come up with a workaround to fix a balky valve in one of the International Space Station’s two coolant loops, NASA managers decided Tuesday to change gears and press ahead with at least two and possibly three spacewalks to replace a refrigerator-size ammonia pump module.
Astronauts Rick Mastracchio, a spacewalk veteran, and first-time flier Mike Hopkins are scheduled to begin the first spacewalk, or EVA, Saturday around 7:10 a.m. EST (GMT-5). The second EVA is planned for Monday with the third, if necessary, on Christmas day.
The decision to carry out multiple spacewalks to repair coolant loop A means a delay for the planned launch of an Orbital Sciences Corp. Antares rocket carrying the company’s Cygnus cargo capsule. Orbital engineers rolled the rocket to its seaside pad at the Mid-Atlantic Regional Spaceport at NASA’s Wallops Island, Va., flight facility early Tuesday for a possible launch try Thursday night.
The flight now will be put on hold until next month.