Astronauts Terry Virts and Butch Wilmore clambered outside the space station in the second spacewalk to reconfigure the station for the commercial crew transport program. The mission was totally successful, until they returned indoors and learned that for the second time, spacesuit #3005 started filing with water.
Virts hard at work, unaware his spacesuit is attempting to drown him. Image credit: NASA
Back in 2013, spacesuit #3005 made a valiant attempt at drowning Italian astronaut Luca Parmitano when a drink bag sprang a leak during a spacewalk. In that incident, he noticed the leak mid-spacewalk, but neither Parmitano nor ground control realized the severity of the problem for a distressingly long time. This time, the water was much less severe: NASA astronaut Terry Virts didn't notice any problem during the spacewalk, and only realized his helmet had free-floating droplets of water and a damp absorption pad after returning to the station. It appears the 15 millilitres of water was the result of condensation during repressurization, a known issue with this particular suit.
Virts greasing up the Canadarm. Image credit: NASA
Currently, the analysis is that this is a known issue, sublimator water carryover, that causes water to condense when the suit is hooked back up to the space station after a spacewalk. NASA's spacewalk officer Alex Kanelakos explained:
"When you connect to the umbilical, you have a lot of cold air that's going past the cooling system of the suit and this air will often condense. And as we repress, we have high-density gas that's flowing past this condensed water that can often move the water over the crew member's helmet.
This spacesuit is known to have what we call carryover water We've had seven other occurrences of this carryover on the spacesuit. … It's not expected every time, but it's a known feature. That's why we monitor a lot of the parameters on the ground. We're continually getting data and we're watching that to see if we're having any occurrences of this situation or the situation that Luca had. And they're very different occurrences."
Sam Cristoforetti helps Terry Virts shed his spacesuit after the spacewalk on February 25, 2015.
Astronaut Samantha Cristoforetti collected the rogue droplets for analysis make sure it's not a bigger problem, but between being far under the 57 millilitre tolerance limit and sublimator water carryover being a known issue with this particular suit, the team is fairly confident in their analysis. In the meantime, the risk assessment is that this isn't a big enough problem to delay the third spacewalk in the sequence, currently scheduled for Sunday. When asked by a reporter if the malfunction made him nervous, Virts expressed total confidence in NASA's safety standards:
"I'm completely confident I'm not going outside unless we're sure it's a good suit."
The 6-hour, 43-minute spacewalk was the second of three preparing to reconfigure the space station with a new hatch in advance of the arrival of space taxis as part of the commercial crew program. Once again, the astronauts are colour-coded for easier identification: Willmore is in a spacesuit with red stripes, with helmet camera 18, and Virts is in the plain spacesuit with helmet camera 20.
The duo finished routing cables necessary for the installation of the new International Docking Adapters later this year. The adapters are necessary to adapt the hatches for new spacecraft arriving in coming decades as part of the commercial crew transport program, and to reduce wear and tear on the space station for years to come.
Virts also spent time lubricating the latching end of the Canadarm, while Wilmore prepared the Tranquility module for the relocation of the Permanent Multipurpose Module and the installation of the Bigelow Expandable Activity Module (BEAM). BEAM will arrive later this year as the start of a two-year experiment evaluating expandable space habitat technology. They also managed to get a bit ahead of their to-do list again, pre-staging wire ties for when they install 122 meters of cable for the Common Communications for Visiting Vehicles (C2V2) system on Sunday.