The Soyuz MS-22 spacecraft, whose thermoregulation system was depressurized in December, will be returned to Earth unmanned while the ISS crew remains aboard, and the station’s mission will continue with an extended stay. This was announced on January 11 by Roscosmos’ top executive, Yuri Borisov.
“After reviewing the vessel’s condition, the technical documentation, and the thermal calculations, it was determined that the MS-22 should land without a crew,” Borisov stated. He added that in a critical scenario at the orbiting station, the state commission will decide which spacecraft would be used to rescue the crew.
Experts from the agency carefully examined the depressurization event in the cooling loop. They determined that the incident resulted from a collision with space debris traveling at roughly 7,000 meters per second, a micrometeoroid impact that breached the radiator system.
The State Commission evaluated several options for evacuating the crew. The first option involved sending Soyuz MS-23 with a pilot and two empty seats, but it would require upgrades and additional documentation, delaying a March 2023 launch.
Ultimately Roscosmos chose an uncrewed MS-23 flight to the station, a plan already feasible by February 20. Consequently, the ISS expedition was extended for the incumbents and the mission timeline was adjusted.
“The crew of Roscosmos cosmonauts Sergei Prokofiev and Dmitry Petelin, along with NASA astronaut Francisco Rubio, will continue the expedition and return to Earth aboard the Soyuz MS-23,” Borisov explained.
Originally, Roscosmos had scheduled a March 16 flight for cosmonauts Oleg Kononenko and Nikolai Chub, with NASA astronaut Loral O’Hara, to board the station aboard Suz MS-23 on that date.
Damage to the skin of the Soyuz MS-22, docked at the ISS, was reported on December 15, 2022. A diagnostic sensor tripped and pressure began to drop in the cooling system. An exterior inspection confirmed a refrigerant leak, which curtailed extravehicular activity but left other systems operating normally.
From the outset, the state company suspected the depressurization could stem from a micrometeoroid striking the radiator in the thermoregulation system.
On December 16, reports circulated that temperatures on the Soyuz climbed to 50 degrees due to a cooling fault. Roscosmos denied the figure, noting a more modest rise to about 30 degrees, with no immediate danger to crew safety.
Officials explained that temperature changes, as observed by the crew, remained within safe margins and did not threaten equipment or the crew’s welfare. The cooling system specific to the Russian segment helped keep living compartments within acceptable limits.
Roskosmos emphasized that there was no threat to the crew and no immediate need to evacuate the ISS. The depressurized MS-22 could be landed without urgency under existing plans.
By December 18, cooling gradually returned toward normal levels after corrective actions. Borisov noted a damaged area on the ship’s outer skin and a hole roughly 0.8 millimeters in diameter. He also praised the cooperation between US and Russian crews during the incident, highlighting the spirit of teamwork on the station.
The head of the agency commented that the ISS team set a global example of collaborative problem solving under pressure. “Let many leaders see how it can be done,” he remarked.
In late December, NASA stated that SpaceX’s Crew Dragon would not be included in the initial evacuation plan for Expedition 68. NASA and Roscosmos continued joint discussions to identify the safest path home for the crew, with stability and wellbeing of the crew remaining the top priority. A NASA spokesperson noted that the current crew was in good condition, continuing repair and research work aboard the station.