The crew of the International Space Station (ISS) was forced to abort a planned spacewalk late on Wednesday when a Soyuz spacecraft docked at the station sprang a leak. The Soyuz leaked coolant for several hours while ground control in Moscow and the ISS crew attempted to get it under control. Teams are still assessing the spacecraft, which is scheduled to transport three of the crew back to Earth in the coming weeks. Potentially more troubling, the Soyuz is the only way to evacuate all seven crewmembers in the event of an emergency.
Cosmonauts Sergey Prokopyev and Dmitri Petelin were suited up and waiting in a depressurized airlock on Wednesday evening when flight control delayed the start of their space walk. Originally, the cosmonauts were supposed to install a radiator on the space station’s Nauka science module. A short time later, they made the decision to postpone the spacewalk, but the Soyuz continued leaking coolant for several more hours.
The leak appeared to originate in an external cooling loop toward the back of the spacecraft, according to Ars Technica. There was no loss of atmosphere like the incident in 2018 that revealed animosity between Russia’s Roscosmos and NASA as the former lobbed vague accusations of sabotage. Instead, the leak sprayed ammonia into space around the station. NASA and Roscomos will no doubt want to check for any possible impact the ammonia might have had on the station and other hardware, but the most pressing issue is what to do about the Soyuz.
Tonight’s spacewalk with cosmonauts Sergey Prokopyev and Dmitri Petelin is on standby as mission controllers assess flakes seen leaking from the Soyuz MS-22 crew ship. pic.twitter.com/jC5X1oaEDh
— International Space Station (@Space_Station) December 15, 2022
The ISS always has at least one Soyuz docked because the venerable spacecraft makes a perfect lifeboat for the crew. All seven astronauts and cosmonauts on the station can board the Soyuz and return safely to Earth — assuming the leak has not damaged the spacecraft. There is also a SpaceX Dragon docked at the station, which delivered four crew members in October, is not large enough to accommodate all seven crew members. The Soyuz capsule is also supposed to return cosmonauts Prokopyev, Petelin, and astronaut Frank Rubio to Earth.
It’s unclear at this time if Roscosmos will send a new Soyuz capsule to the station. It could take time to prep such a launch, and that would leave the crew vulnerable in the interim. NASA stresses that there is no cause for alarm at this time — the crew is safe aboard the ISS and were not in any danger during the leak.