‘Arctic explosion’ from leaking water halts NASA astronauts’ spacewalk

A spacewalk by two NASA astronauts on the International Space Station ended almost immediately Monday morning when water began spraying from one of their spacesuits into the airlock.

“There’s water everywhere,” Tracy Dyson, one of the astronauts, reported to mission control.

That was a few minutes after she and Mike Barratt, the other astronaut participating in the spacewalk, switched their spacesuits to battery power, beginning the spacewalk at 8:46 a.m. Eastern Time.

“I got an arctic blast all over my visor,” Ms. Dyson reported.

She wiped away a layer of ice, allowing her to see ice crystals coming from a service-and-cooling umbilical unit connected to her space suit. The connections provide power, oxygen and water while astronauts are in the airlock. The leak started when Mrs Dyson unplugged the unit.

“I could see the ice crystals flowing there,” Ms Dyson said. “Just like a snow cone machine, ice formed at that gate.”

The space station controllers in Houston then canceled the spacewalk. NASA said the astronauts were never in danger.

The shortened spacewalk was the latest in a series of disruptions NASA has experienced this month. Other problems included a previously postponed spacewalk and delays in the return of two astronauts to Earth aboard a Boeing space capsule known as Starliner, which is on its maiden voyage to the space station with astronauts on board.

On Monday the leak stopped when Mrs Dyson reconnected the umbilical cord. She and Mr Barratt were back on the space station and out of their spacesuits 45 minutes later. Although they never floated outside the hatch, they were still assigned a 31-minute spacewalk – the time from when they turned on the internal batteries to when the airlock was repressurized.

They would spend six and a half hours outside. Their main tasks were to remove a faulty electronics box from a communications antenna and collect samples from the space station’s exterior as part of scientific research to see if microorganisms can survive the harsh, airless, radiation-ridden environment of space .

It was the second interrupted spacewalk this month for Ms. Dyson. She and Matthew Dominick, another NASA astronaut currently on the space station, were scheduled to conduct the spacewalk on June 13, but it was postponed after Mr. Dominick reported a “spacesuit problem.”

NASA provided no additional details about what happened, and Mr. Barratt subsequently replaced Mr. Dominick, who was already scheduled to participate in another spacewalk. “We had a suit ready for him,” Dana Weigel, NASA’s space station program manager, said at a June 18 news conference. “We decided it was wise to go ahead and use Tracy and Mike.”

NASA has scheduled another spacewalk for July 2, but those plans could now change.

The spacesuits NASA astronauts currently wear during spacewalks are more than four decades old, dating back to the early space shuttle era. The space agency has hired Collins Aerospace to provide replacement suits for use on the space station. (A different company, Axiom Space, is developing spacesuits for NASA astronauts to wear when they walk on the moon.)

Failures of current spacesuits are rare, but potentially serious. In 2013, European Space Agency astronaut Luca Parmitano nearly drowned when water pooled in his helmet after a fan pump became blocked. Monday’s problem involved a different part of the space suit.

NASA managers are also still trying to understand the problems Boeing’s Starliner spacecraft is experiencing. Carrying two NASA astronauts, Butch Wilmore and Suni Williams, Starliner successfully docked with the space station on June 6. The mission is part of a test flight of the spacecraft, and Starliner’s propulsion system has leaked helium, which is used to push fuel to the thrusters, five times. Several thrusters also malfunctioned as Starliner approached docking.

Boeing and NASA engineers believe the helium leaks are minor and will not pose a serious problem during the return trip. All but one of the thrusters now appear to be working well after short test shots a week ago.

However, NASA managers also decided to spend more time reviewing the data and postponed the return to a date in July, at the earliest. The Starliner spacecraft has been approved for 45 days of docking with the space station, or until July 21. The mission was originally scheduled to last just eight days, and Mr. Wilmore and Ms. Williams have now been on the space station for 18 days.