Spacewalk Of Russian Cosmonauts Outside ISS Cancelled Due To Coolant Leak From Docked Soyuz

The aim of the spacewalk was to relocate a radiator from the Rassvet module to the Nauka science module on the Russia segment of the ISS. The ISS crew members were not in any danger during the leak.

Russian spacewalk: The planned spacewalk by Roscosmos cosmonauts Sergey Prokopyev and Dmitri Petelin on December 14 (according to Eastern Standard Time) was cancelled due to the leak of a coolant leak from the Soyuz MS-22 spacecraft docked to the Rassvet module on the International Space Station (ISS). Mission Control teams in Moscow are assessing the coolant leak from the aft end of the spacecraft, NASA says on its website. 

A NASA webcast showed a stream of liquid ejecting from the Soyuz spacecraft. The spray of fluid appeared like a "torrent of snowflake-like particles" emanating from the rear section of Soyuz MS-22, according to a report by news agency Reuters. 

In order to allow time to evaluate the fluid and potential impacts to the integrity of the Soyuz spacecraft, the spacewalk was cancelled. The crew members aboard the orbital laboratory were not in any danger during the leak, and are safe, NASA says. 

Why was the spacewalk planned?

The aim of the spacewalk was to relocate a radiator from the Rassvet module to the Nauka science module on the Russia segment of the ISS. 

Rob Navias, the NASA commentator on the livestream mentioning the leak, said the leak, because of which the spacewalk was cancelled, began at about 7:45 pm EST on December 14 (7:15 am IST on December 15). 

According to the Reuters report, Navias said the spacewalk was postponed once before, in late November, due to faulty cooling pumps in the cosmonauts' spacesuits.

This spacewalk would have been the 12th this year, and the 257th for space station assembly, maintenance and upgrades, according to NASA. This would have been the fourth spacewalk in Prokopyev's career, and the second for Petelin. 

On September 21, NASA astronaut Frank Rubio and Roscosmos cosmonauts Prokopyev and Petelin were launched into space aboard the Soyuz MS-22 spacecraft, from the Baikonur Cosmodrome in Kazakhstan. 

Other spacecraft docked to the ISS are Cygnus-18, Crew-5 Dragon, CRS-26 Cargo Dragon, Progress 82 and Progress 81.

The launch of the Surface Water and Ocean Topography (SWOT) mission has also been delayed. NASA, the French space agency Centre National d'Études Spatiales, and SpaceX now aim to launch the mission on Friday, December 16.