A planned cosmonaut spacewalk has been cancelled due to ground controllers discovering a leak.
Ground teams noticed significant leaking of an unknown substance from the aft portion of the Soyuz MS-22 spacecraft during preparations for a spacewalk on December 14, according to NASA. The spacecraft was docked on the Rassvet module on the International Space Station.
This spacewalk was to be undertaken by Roscosmos cosmonauts Sergey Prokopyev and Dmitri Petelin.
The spacewalk was subsequently cancelled, and ground teams in Moscow began to evaluate the nature of the fluid and the integrity of the spacecraft.
This is the second time the spacewalk was cancelled; the first was planned for November 25. The spacewalk was aborted after an issue with a cooling pump was discovered in the space suit of Prokopyev.
The leak was traced back to the coolant system of the spacecraft and was detected on December 14 about two hours before the spacewalk. The external radiator cooling loop of the Soyuz is suspected to be the source of the leak.
Roscosmos is monitoring Soyuz spacecraft temperatures, which remain acceptable. NASA and Roscosmos are coordinating external imagery and inspection plans to evaluate the location of the leak.
“Experts in Moscow are going to be taking a look at their systems and responding to the leak according to their procedures and policies,” said Emily Nelson, NASA space station flight director. “Once they have a good understanding of the final status of the Soyuz tonight, we will then jointly make a decision about where to go forward from here,” she continued.
The cosmonauts did not exit the space station and none of the crew on board are reported to be in any danger.
The Soyuz spacecraft carried NASA astronaut Franko Rubio and Roscosmos cosmonauts Sergey Prokopyev and Dmitri Petelin to the ISS after launching from the Baikonur Cosmodrome in Kazakhstan on September 21. The spacecraft also serves as an escape vessel in the event of an emergency aboard the space station requiring evacuation.
The spacewalk is now indefinitely postponed while the Soyuz spacecraft is evaluated.
A U.S. spacewalk is expected to take place on December 19.