An unexplained leak was spotted from one of Russia's Soyuz spacecraft docked at the International Space Station (ISS), which forced the cosmonauts to cancel their scheduled spacewalk as ground controllers worked to troubleshoot the problem.

A NASA commentator has described the problem as a coolant leak for the Soyuz MS-22 spacecraft, which was first detected on Wednesday, December 14, at 7:45 pm EST. NASA also clarified that none of the members of the ISS were injured or in danger due to the leak.

 Cosmonauts' Spacewalk at the International Space Station Cancelled Due to Unexplained Leak From Docked Soyuz Spacecraft
(Photo: Pixabay/WikiImages)
Cosmonauts' Spacewalk at the International Space Station Cancelled Due to Unexplained Leak From Docked Soyuz Spacecraft


Coolant Leak from the Soyuz Spacecraft

The leak was found an hour and 40 minutes before Expedition 68 crewmates Sergey Prokopyev and Dmitry Petelin of Roscosmos were scheduled for their 6-hour and 40-minute spacewalk. But due to the leak, the two cosmonauts reportedly already preparing for the extravehicular activity had to cancel and reschedule it.

Prokopyev and Petelin depressurized the airlock and reentered the space station when the leak was found, Space.com reported. Cameras on the space station's exterior showed a steady stream of frozen flakes ejected from the Soyuz spacecraft. It was believed to be from the exterior coolant system near the aft section of the spacecraft. NASA spokesperson Rob Navias said that the cause of the leak is not yet known, but Russian specialists are continuing to look at the data and are currently discussing possibilities of what could have caused it.

Flight controllers ensured that every crew member in the space station was safe. However, the leak continued for at least three hours. They promised updates via NASA's blog and social media channels regarding the coolant leak.

Once Roscosmos has a good understanding of the final status of the Soyuz spacecraft, NASA will jointly decide where to go forward from there. Cosmonaut Anna Kikina used the outpost's European Robotic Arm on its Russian segment to inspect the leak as engineers at the control center in Moscow reviewed its telemetry and data.

READ ALSO: NASA to Resume Spacewalk Outside International Space Station After 5 Months

Cosmonauts' Spacewalk Canceled for the Second Time

It was the second time that Prokopyev and Petelin had to cancel their spacewalk, which was scheduled to relocate a radiator from one Russian module to another. Their extravehicular activity was initially planned on November 24 when an issue with a water coolant pump on the spacesuit of Prokopyev was detected.

As per ABC News, the spacewalk was to be the 12th at the space station this year and the 257th in history for the assembly, maintenance, and upgrade work on the space station. Roscosmos could send an uncrewed spacecraft and autonomously dock it to the space station.

There are currently five other spacecraft parked at the ISS, including SpaceX's Crew Dragon and Cargo Dragon, a Northrop Grumman Cygnus, and two Russian resupply ships, Progress 81 and 82.

RELATED ARTICLE: Russian Cosmonauts Successfully Complete First of Two Spacewalks to Activate European Robotic Arms in ISS

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