A coolant leak on a Russian Soyuz space capsule docked at the International Space Station (ISS) was reportedly caused by a hole less than 0.8 millimeters (0.03 inches) in diameter and it did not require crew evacuation, announced Russia's space corporation, Roscosmos, but the agency was open to the possibility of launching a replacement capsule if needed.
Roscosmos said a panel of experts would determine later this month whether the Soyuz MS-22 capsule could be safely used by crew for its planned return to Earth, or if it should be discarded and replaced.
It said the next scheduled Soyuz launch was March but could be expedited if necessary.
The leak in the Soyuz MS-22 was spotted last week when a pair of Russian cosmonauts were about to venture outside the station on a planned spacewalk. The Russian Mission Control aborted the spacewalk when ground specialists sighted a stream of fluid and particles emanating from the Soyuz on a live video feed from space.
Both Roscosmos and NASA have said that the incident has not posed any danger to station crew.
Roscosmos said the leak might have been caused by a micrometeorite or a piece of space junk striking one of the capsule's external radiators.
As per a Roscosmos statement on Monday, the leak caused the temperature in the crew section of the capsule to rise to 30 degrees Celsius (86 degrees Fahrenheit). The temperature in the equipment section initially soared to 40 degrees Celsius but dropped to 30 degrees Celsius after ground experts switched some of the capsule's systems.
Roscosmos said the crew used ventilators in the Russian segment to blow cold air into the capsule to reduce cockpit temperature to comfortable levels.
"The temperature increase onboard the Soyuz MS-22 spacecraft is admissible and is not critical for the functioning of the equipment or health of crew in case they need to be onboard the spacecraft," Roscosmos clarified, adding that tests of the ship's control system determined it was not affected by the incident.
The space corporation said an inspection of the capsule surface with a camera on a Canadian-built robotic arm helped spot the location of the coolant leak.
Prokopyev, Petelin and NASA astronaut Frank Rubio used the Soyuz MS-22 to arrive at the International Space Station in September, and it has served as a lifeboat for the crew. The capsule was scheduled to ferry them back to Earth in March as part of regular rotations.
Roscosmos said the next Soyuz spacecraft, the Soyuz MS-23, has already undergone some preparatory tests for a previously scheduled launch in March and added that the launch could be expedited if necessary.
Roscosmos director, Yuri Borisov, told reporters on Monday that specialists would analyze the ship's condition and take a decision on how to proceed around Dec. 27. He said the hole in the Soyuz was just 0.8 millimeters (0.03 inches).
"If the situation is under control and we are fully certain of the ship’s ability, it will be used for the scheduled return of the crew. If the situation takes a different turn, we obviously have reserve options," said Borisov.
Along with Prokopyev, Petelin and Rubio, four other crew members are currently on the space outpost including NASA astronauts Nicole Mann and Josh Cassada; the Japan Aerospace Exploration Agency’s Koichi Wakata; and Anna Kikina of Roscosmos.