A micrometeorite may have hit the International Space Station’s Soyuz spacecraft

An external cooling loop on the Soyuz spacecraft, attached to the Earth-facing side of the International Space Station, may have been hit by a tiny meteorite, causing coolant to leak into space. The leak, discovered Wednesday evening, forced the cancellation of a planned spacewalk by Russian cosmonauts Sergey Prokopyev and Dmitry Petelin, according to NASA.

The spacewalk was scheduled to take place at 6:00 p.m. PT to move a heat-dissipating radiator from the Rassvet module, where the Soyuz is docked, to the recently installed Nauka general-purpose laboratory module, but a stream of particles was visible in the vision . of the MS-22 Soyuz on a NASA live feed. The astronauts on board were not injured and the space station is in good condition, NASA said in a tweet Wednesday night.

“Tonight’s spacewalk has been canceled due to an observed leak of what is believed to be a coolant,” Rob Navias of NASA communications said on the broadcast.

The spacecraft carried Prokopyev and Petelin to the station on September 21, along with NASA astronaut Frank Rubio, for the Soyuz MS-22 mission.

Navias said on the show that the flakes were “indicative of a leak”, but the substance was not confirmed. The leak coincided with a pressure drop, first detected around 4:45 p.m. PT, in one of the spacecraft’s external cooling loops. Experts from NASA and Roscosmos in Moscow are coordinating to examine the leak and will assess whether it caused any damage to the integrity of the Soyuz spacecraft. The robotic Canadarm2 will be used to inspect the exterior of the capsule.

According to the Associated Press, Russian director of crewed spaceflight Sergei Krikalev suggested that a meteorite impact may have caused the coolant leak.

Micrometeorites are a constant presence in space and constantly bombard the Earth. Even the James Webb Space Telescope has to deal with the tiny fragments of rock and dust. For the most part, they do little damage, and spacecraft and astronauts are protected by armor or suits. However, if a micrometeorite hits a coolant pipe or radiator at a right angle, it could lead to a leak. There is also the possibility that a piece of rogue space junk collided with the Soyuz capsule. Until a full inspection takes place, it is impossible to know.

This is the second time the spacewalk to move the radiator has been canceled. Originally, the cosmonauts were to perform their work on November 25, but there was a problem with the water cooling loops in the cosmonaut suits. Another Russian spacewalk, scheduled for December 21, has also been canceled, but a US spacewalk is still scheduled for December 19.

Update December 15: Additional details from the NASA blog.