Date: Apr 09, 2019
Two astronauts floated outside the International Space Station Monday for NASA’s third spacewalk in less than three weeks, this one to help replace a faulty solar array battery that was installed during the first excursion, to route ethernet cabling to extend wireless connectivity and to install backup power lines for the lab’s robot arm.
Floating in the Quest airlock, NASA flight engineer Anne McClain, call sign EV-1, and Canadian astronaut David Saint-Jacques, EV-2, switched their spacesuits to battery power at 7:31 a.m. EDT, officially kicking off what turned out to be a six-hour 29-minute excursion, the 216th since station assembly began in 1998.
The spacewalkers accomplished all of their primary objectives without any major problems. McClain had a bit of trouble clearly hearing mission control toward the end of the excursion and reported moisture on her helmet visor after returning to the airlock. But she said there were no signs of an actual water leak that might pose a safety threat.
Saint-Jacques originally planned to conduct Monday’s spacewalk with NASA astronaut Nick Hague. Hague and McClain carried out the first of the three spacewalks March 22 while McClain and Christina Koch planned to carry out the second on March 29, becoming the first all-female spacewalk team in space history.
But after the first excursion, McClain decided she was more comfortable wearing a medium-size suit, the same one Koch needed. Because it would take nearly a full crew day to re-size a spare suit to fit McClain, Hague took her place on the second spacewalk and McClain replaced him for the third outing.
As it turned out, the crew swaps were just one of the changes the crew had to deal with.
During the March 22 spacewalk, McClain and Hague followed up work with the station’s robot arm to replace six older nickel-hydrogen batteries in the lab’s solar power system with three more efficient lithium-ion batteries. The astronauts installed “adapter plates” permitting a single li-ion battery to take the place of two of the older nickel-hydrogen power packs.
