Jan. 15, 2016 — A spacewalk outside of the International Space Station was terminated on Friday (Jan. 15) after an astronaut reported a small water bubble forming inside his spacesuit's helmet.
NASA astronaut Tim Kopra called down to Mission Control in Houston just before 11:00 a.m. CST (1700 GMT) to alert about the leak, noting that the water was about 3 inches (8 cm) above his head. By moving, he was able to come into contact with the water and noted it was cold, a sign that it might be coming from his portable life support backpack.
"We're in a terminate case," radioed NASA astronaut Reid Wiseman in Mission Control, relaying Flight Director Royce Renfrew's decision. "We want you to start heading back to the airlock."
Although Kopra was not in any immediate danger, ground controllers followed the procedures that were put in place after a much more severe leak developed during an earlier spacewalk. On July 16, 2013, a significant amount of water entered the helmet of Italian astronaut Luca Parmitano, a problem later traced back to a contamination-clogged filter.
NASA astronaut Tim Kopra seen during the Jan. 15 spacewalk. The EVA ended early after a water bubble formed in his helmet. (NASA) |
As a response to that case, absorption pads were installed in the helmets as a way to capture small leaks, as well as provide the means for spacewalking astronauts to perform periodic checks for water.
In addition to reporting the bubble, Kopra also said his pad was wet.
The cause of the water leak on Friday was not immediately known. Early in the spacewalk, a carbon dioxide sensor in Kopra's spacesuit failed, which may have been a symptom of the leak.
The space station's crew collected water samples from the helmet to help with the investigation.
Kopra, who with European Space Agency (ESA) astronaut Tim Peake began the spacewalk at 6:38 a.m. CST (1238 GMT), safely made it back inside the space station's Quest airlock four hours and 43 minutes later. The extravehicular activity, or EVA, had been slated for six and a half hours.
Before the leak began and the spacewalk was terminated, Kopra and Peake did carry out the replacement of a failed voltage regulator, called a sequential shunt unit, which was the major objective of the EVA.
Swapping the units during a night pass, given the voltage regulator's solar power supply and the potential for a short inside the faulty box, Kopra and Peake completed the job about two hours into the spacewalk.
NASA astronaut Tim Kopra seen during the Jan. 15 spacewalk. The EVA ended early after a water bubble formed in his helmet. (NASA) |
"Guys, we have got great news down here that the SSU is performing as expected with the Sun up. Everything looks really good," reported Wiseman, who performed a similar repair for a different power channel on the space station in 2014.
"Awesome," replied Kopra.
When Kopra detected the water bubble in his helmet, he had just completed his second task, installing a vent on the side of the Tranquility node. Peake, meanwhile, had begun deploying cables for the future addition of an international docking adapter that will enable U.S. commercial crewed vehicles to visit the station.
With the call to end the EVA, Peake tied down the cables where he was, leaving that work to be completed during a future spacewalk. The two astronauts were also slated to retrieve a light from a truss camera and release a bolt on a pressurized mating adapter.
Kopra and Peake completed the 35th U.S. increment EVA out of the Quest airlock and the 192nd spacewalk overall in support of the International Space Station since 1998.
The spacewalk was Kopra's third, after EVAs in 2009 and late last year. His total time working outside in the vacuum of space is now 13 hours and 31 minutes.
Tim Peake was the first British astronaut to wear a Union Jack flag on his spacesuit during the Jan. 15 spacewalk. (NASA) |
Peake, who was making his first-ever spacewalk, was the tenth member of the ESA's astronaut corps to go EVA after crew members from France, Germany, Italy, Sweden and Switzerland. He was the first British astronaut to wear the United Kingdom's flag on his spacesuit.
"Tim, it is really cool seeing that Union Jack go outside. It has explored all over the world, and now it has explored space," said Scott Kelly, the space station's Expedition 46 commander, just as Peake exited the Quest airlock at the start of the spacewalk.
"It is great to be wearing it, a privilege," replied Peake. "A proud moment."
