U.S. Spacewalk Postponed as Investigation Continues into Soyuz Leak

NASA said this afternoon that it will delay a planned International Space Station spacewalk on Monday as it works with its Russian counterpart, Roscosmos, to investigate the cause of a dramatic coolant leak on Russia’s Soyuz MS-22 spacecraft. Instead, on Sunday, NASA will use the robotic Canadarm2 to take a look at the Soyuz to assess the spacecraft’s status and try to determine what caused the leak. Three ISS crewmembers — two Russians and one American — need that spacecraft to bring them back to Earth.

On Wednesday evening at about 7:45 pm ET, just as two Russian cosmonauts were getting ready to exit the space station to conduct a spacewalk, warnings sounded that the pressure was dropping in a cooling loop on the Soyuz spacecraft docked just outside the airlock.

It quickly became visually apparent that a significant amount of something was leaking from the Soyuz.

Russia called off the spacewalk by cosmonauts Sergey Prokopyev and Dmitri Petelin, the second of four they are scheduled to conduct to continue outfitting the newest Russian module, Nauka, that arrived at the ISS in July 2021.

For the past two days, the two space agencies have been working closely together to figure out what happened and determine if the Soyuz is still safe to use. Not only was it the ride up to the ISS for Prokopyev, Petelin, and NASA astronaut Frank Rubio in September, but it is their ride back home in March and their lifeboat in between. Emergencies can happen at any time on the space station and every crew member must be able to seek shelter and undock and return to Earth if necessary.

Four other crew members are aboard right now: NASA’s Nicole Mann and Josh Cassada, JAXA’s Koichi Wakata, and Russia’s Anna Kikina. They arrived on a SpaceX Crew Dragon and will return the same way. Crew Dragon is their lifeboat.

The United States and Russia signed a crew exchange agreement this summer where astronauts fly on Russian Soyuz spacecraft in exchange for Russians flying on American spacecraft, resuming the practice that existed in the early days of the space station program. The Russian and U.S. segments of ISS are co-dependent and at least one crew member from each country is needed aboard at all times to keep it operating. NASA paid Russia to ferry astronauts to and from the ISS for more than a decade, especially after the space shuttle was terminated and there was no alternative, but now that Crew Dragon is operational, the situation has returned to cooperation on a no-exchange-of-funds basis.

NASA emphasizes that none of the crewmembers are in any danger because of the Soyuz leak at this time.

Russia’s Nauka module has its own robotic arm provided through a cooperative agreement with the European Space Agency. Kikina used the European Robotic Arm to survey Soyuz while the leak was still occurring.

But NASA said today they want to get more images using Canadarm2.

All the coolant had leaked out as of yesterday at about 1:30 pm ET, about 18 hours after it started.

This morning at 3:18 am ET, Russia test-fired the Soyuz thrusters and they checked out OK. Roscosmos continues to assess other Soyuz systems. NASA said temperatures and humidity inside the spacecraft are “within acceptable limits.”

Katya Pavlushchenko, a space enthusiast in Russia who translates information issued by Roscosmos and Russian news organizations and shares it on Twitter, pointed out that Roscosmos challenged a report today in Russia’s RIA Novosti newspaper that temperatures inside Soyuz had risen to 50° Celsius (122° Fahrenheit) and instead are 30°C (86°F).

Roscosmos stated that the information by RIA Novosti about the temperature of 50 C in #SoyuzMS22 is NOT TRUE: https://t.co/uhPJaTV5vh They say, the temperature is about 30 C. pic.twitter.com/DbUdo0hVKZ

— Katya Pavlushchenko (@katlinegrey) December 16, 2022

Temperatures inside the spacecraft are important not only in terms of putting people in there, but the effect on computers and other electronics needed to bring the spacecraft back to Earth.

Russia’s state news agency TASS reported this afternoon that Roscosmos sent updated procedures for using Soyuz for an emergency evacuation to the crew today but “there is no need to use them at the moment” and such updating is done “on a regular basis.”

The next step is to take as close a look as possible to see if there’s any evidence of what caused the leak. There is a lot of speculation that it could have been an impact from a micrometeoroid or space debris, but that is not confirmed. TASS said “the outer plating of the instrument and equipment compartment of the Soyuz MS-22 crewed spacecraft docked to the ISS was damaged.”

The inspection by Canadarm2 will happen on Sunday. Canadarm2 also is needed to support the upcoming U.S. spacewalk by Rubio and Cassada to install another ISS Roll Out Solar Array (iROSA), so that’s been postponed from Monday to Wednesday.

The ISS is a partnership among the United States, Russia, Canada, Japan, and 11 European countries working through ESA. The “U.S.” segment includes modules from Europe and Japan plus Canada’s Canadarm2.