An unexplained leak from a docked Soyuz spacecraft cancels a Russian spacewalk aboard the International Space Station

(Reuters) – A routine spacewalk by two Russian cosmonauts aboard the International Space Station (ISS) has been canceled as it was about to begin, after flight controllers noticed a gush of liquid from a spacecraft, a NASA webcast showed. Soyuz moored.

The liquid spray, which was visible on NASA’s live video feed as a torrent of ice-like particles emanating from the back of the Soyuz MS-22 capsule, was described by a NASA commentator as a coolant leak.

NASA said that none of the seven current ISS crew members — three Russian astronauts, three American astronauts and a Japanese astronaut — were ever in any danger.

The accident occurred when two cosmonauts, Crew Commander Sergey Prokopyev and Flight Engineer Dmitry Petlin, were suiting up and preparing for a planned spacewalk to transfer coolant from one module to another on the Russian portion of the International Space Station.

An official for Russian mission control operations near Moscow was heard telling Prokopyev and Beitlin on a radio transmission that their spacewalk had been canceled while engineers worked to determine the nature and origin of the leak.

Broadcasting from NASA’s Johnson Space Center in Houston, NASA live commentator Rob Navias said the spacewalk was canceled because of the leak, which he said began around 7:45 p.m. EDT (0145 GMT Thursday). .

Navias said the Soyuz craft arrived at the space station in September, brought Prokopyev, Betlin and US astronaut Frank Rubio to the ISS, and remained attached to the Earth-facing side of the orbiting laboratory.

Navias said a spacewalk planned for Wednesday had been delayed once before, in late November, due to faulty cooling pumps in the astronauts’ suits.

It was scheduled to be the 12th spacewalk this year on the International Space Station and the 257th in the history of the 22-year-old platform for assembly, maintenance and modernization, according to NASA.

Navias said it’s too early to tell what implications the leak might have for the safety of that spacecraft, and whether it will present any difficulties for the crew’s return to Earth at the end of their mission.

Five other spacecraft are parked on the space station—two SpaceX capsules (Crew Dragon and Cargo Dragon), a Northrop Grumman Cygnus space cargo ship, and two Russian resupply ships, Progress 81 and Progress 82.

The International Space Station, which stretches the length of an American football field and orbits about 250 miles above Earth, has been continuously occupied since 2000, and is operated by a US-Russian-led partnership that includes Canada, Japan and 11 European countries.

(Reporting by Steve Gorman in Los Angeles). Additional reporting by Joe Roulet in Washington. Editing by Jerry Doyle

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