Russian Cosmonauts’ ISS Spacewalk Canceled Following Soyuz Coolant Leak

Russian cosmonauts may not be going on a spacewalk on the International Space Station anytime soon.

NASA recently revealed that Russia's Soyuz craft was leaking coolant into space while it was docked on the ISS, preventing them from executing a spacewalk outside the facility.

The spacewalk was supposed to take place at 6 PM PT on Dec. 14. to do some minor adjustments on the ISS' many instruments, per CNET.

Soyuz Spacecraft Coolant Leak Details

NASA mentioned in a blog post that its ground teams noticed a significant amount of liquid leaking from the aft portion of the Soyuz MS-22 spacecraft docked to the Rassvet module on the ISS.

This liquid is said to be leaking "fairly substantially" from the Soyuz, and could possibly be its coolant, according to NASA public affairs officer Rob Navias, who was commentating on the spacewalk for NASA Television, per Ars Technica.

Navias mentioned that the liquid leaking from the Soyuz was ammonia - which Russia used as a spacecraft coolant.

Although Russian officials did not give a statement on what the nature of the liquid is, NASA ground teams noticed it in time for the scheduled spacewalk of Russian cosmonauts Sergey Prokopyev and Dmitri Petelin.

Based on what NASA was showing live at the time, both cosmonauts were already dressed in their spacesuits, with the ISS' airlock depressurized.

When NASA ground teams spotted the leak, they had the cosmonauts halt mid-procedure to assess the damage and see where the leak came from. After this impromptu investigation, NASA ground teams called off the spacewalk shortly before 10 PM ET.

The spacewalk was originally planned to move a heat-dissipating radiator from the Rassvet module to Russia's Nauka multi-purpose laboratory module.

Thanks to this delay and cancelation, Prokopyev and Petelin were not exposed to any unnecessary levels of danger. Additionally, Anna Kikina, NASA astronauts Frank Rubio, Nicole Mann, and Josh Cassada, as well as Koichi Wakata, were not in danger at any time when Soyuz was docked on the ISS.

How To Return To Earth?

Although Russia's cosmonauts are safe from the dangers posed by the leak on the Soyuz spacecraft, it does beg the question of what would Russia use to return to the surface of the Earth.

Prokopyev, Petelin, and NASA Frank Rubio are said to be joining each other for a return trip to Earth next spring.

Thankfully, Russia does have a plan for such an occasion. Should Russian and NASA engineers determine that there is an issue with the return spacecraft, would launch and fly a replacement Soyuz to pick them up and take them back to Earth's surface.

Regardless, this is the second attempt ISS crew members made to move the radiator that was canceled. The first was supposed to happen on Nov. 25, but a problem with the water cooling loops in the cosmonaut's suits forced them to reschedule for Dec. 13.