Unexplained leak from docked spacecraft cancels Russian ISS spacewalk - The Jerusalem Post

A routine spacewalk by two Russian cosmonauts aboard the International Space Station (ISS) was called off as it was about to begin after flight controllers noticed a stream of liquid spewing from a docked Soyuz spacecraft, a NASA webcast showed.

The spray of fluid, which was visible in NASA's live video feed as a torrent of snowflake-like particles emanating from the rear section of the Soyuz MS-22 capsule, was described by a NASA commentator as a coolant leak.

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  An ISS spacewalk by two Russian cosmonauts has been cancelled for technical reasons, Russia’s state-run space corporation told reporters on Thursday.

"A spacewalk by cosmonauts Sergey Prokopyev and Dmitry Petelin outside the International Space Station (ISS), scheduled by Russia, has been cancelled for technical reasons," Roscosmos said.

The decision to end a Russian spacewalk was earlier reported by a Mission Control Center expert taking part in space-to-ground communications with the space crew, streamed by NASA.

"It was decided to cut the spacewalk [outside the ISS] short," he said.

Preparations for the spacewalk were cancelled because of leaking of an unknown substance from the aft portion of the Soyuz spacecraft docked to the ISS. "We are trying to understand the situation, we are trying to make additional remote measurements to see how critical things are, the guys know about this," said the expert involved in communications with female cosmonaut Anna Kikina. The spacecraft remains secure inside, he added.

The cosmonauts were scheduled to open the hatch of the Poisk mini-research module at 5:20 a.m. Moscow time on Thursday, and spend six and a half hours outside the ISS. During the spacewalk, a heat exchanger was to be transferred from the Rassvet mini-research module to the Nauka multipurpose lab on the ISS Russian segment transfer with the help of the ERA robotic arm.