NASA astronauts tackle urgent spacewalking repairs
In the days following the Dec. 11 breakdown, flight controllers attempted in vain to fix the bad valve through remote commanding. Then they tried using a different valve to regulate the temperature of the overly cold loop, with some success. But last Tuesday, NASA decided the situation was severe enough to press ahead with the spacewalks. Although the astronauts were safe and comfortable, NASA did not want to risk another failure and a potential loss of the entire cooling system, needed to radiate the heat generated by on-board equipment.
NASA delayed a delivery mission from Wallops Island, Va., to accommodate the spacewalks. That flight by Orbital Sciences Corp., which should have occurred this past week, is now targeted for Jan. 7.
Until Saturday, U.S. spacewalks had been on hold since July, when an Italian astronaut's helmet was flooded with water from the cooling system of his suit. Luca Parmitano barely got back inside alive.
Engineers traced the problem to a device in the suit that turned out to be contaminated — how and why, no one yet knows.
For Saturday's spacewalk, Hopkins wore Parmitano's suit, albeit with newly installed and thoroughly tested components.
Just in case, NASA had Mastracchio and Hopkins build snorkels out of plastic tubing from their suits, before going out. The snorkels will be used in case water starts building up in their helmets. They also put absorbent pads in their helmets; the pads were launched from Earth following the July scare.
Besides the two Americans, three Russian and one Japanese astronaut are living on the space station, all men.