After several months of waiting, the Russian agency Roscosmos announced the departure of a Soyuz rescue vessel to the International Space Station (ISS) on February 24. Last December, a spectacular leak of coolant from the Soyuz capsule was spotted. The spacecraft was supposed to bring American Frank Rubio and Russians Sergei Prokopiev and Dmitri Peteline back to earth in March, after six months in space. So what is the danger of this incident, and why did the Russian agency take so long to come to a decision?
Dangerous return and lifeboat
“A leak in the cooling system of a shuttle poses a problem for the comfort, even the safety of the astronauts, since the temperature can rise very high. But in addition to cooling the artificial atmosphere of the capsule, the cooling circuit serves to keep the electronic systems functional and to guarantee the correct piloting on the way back”, explains to The Express Jean-François Clervoy, astronaut and founder of Air Zéro G. He himself made three flights aboard spacecraft launched by NASA.
This technical incident is problematic for two reasons. When a team arrives on the ISS, the spacecraft that brought it up then takes on the role of lifeboat for the six months that each mission lasts. “All astronauts on board the ISS must be able to have a means of returning to earth in the event of an emergency. Having a defective spacecraft is like having a non-functional life raft”, explains the astronaut. Two transport vessels are currently docked at the station: the damaged Russian Soyuz spacecraft (3 places), and the American Crew Dragon (4 places). However, the American Crew Dragon cannot contain the 7 astronauts currently present on the ISS in the event of evacuation. “It would still be possible for the Russian crew to leave on board the damaged Soyuz, but we cannot be sure that they are 100% safe there,” continues Jean-François Clervoy.
If the station’s engineers think that the Soyuz remains flyable and watertight, the Roscomos agency has finally made the decision, after several months, not to risk a technical problem on the way back to earth. In this context, “the Council of Leading Aerospace Designers recommended to the State Commission to schedule the launch of the Soyuz MS-23 spacecraft from Baikonur on February 24 at 03:34 Moscow time,” Roscomos announced on Sunday 19 FEBRUARY. A flight was originally scheduled for February 20, before being slightly postponed.
Astronaut mission extended
A new Soyuz should therefore replace the damaged shuttle. But the three astronauts, who were supposed to return to earth on March 28, will ultimately have to stay an additional six months on the ISS. “The return flight is scheduled to take place aboard Soyuz MS-23 in September 2023,” Roscosmos said in a statement on Tuesday. The usual duration of a mission on the ISS is however usually six months maximum. “Sending a brand new ship empty to get the crew in right away would be wasting an investment in an expensive shuttle and flight. The Russian agency would probably prefer to ask the crew to stay six more months to operate potential of this new shuttle”, suggests Jean-François Clervoy. According to Roscosmos, this extension of the mission time does not present a danger to the health of the crew, “who perceive this extension positively”.
But why did the Roscomos agency wait several months between March 2022 and February 2023 before deciding to launch a new ship? And this despite the risk incurred by the astronauts in the event of an emergency departure which should have taken place on board the damaged Soyuz. “We can’t say for certain, but the answer could be that the Soyuz spacecraft are not being built on the assembly line. It is possible that they simply did not have new ones on hand until then. They also took the time to check the level of damage to the shuttle docked at the station,” said the astronaut.
Doubts settle on the quality of Russian ships
“To sum up, the situation is worrying, but not immediately dangerous for astronauts,” said Alain Cirou, editorial director of the specialized magazine Sky and Space. Another factor bothers the observer more. In mid-February, another leak was spotted aboard a second Russian vessel, the Progress MS-21 cargo vessel, also docked at the station. This leak also concerns the coolant.
“The first leak spotted on the Soyuz had been attributed to the impact of a micro-asteroid. But now with two similar technical problems, the international space community is asking the question of the quality control of Russian vessels”, point- he. “The Russians will therefore have to be particularly vigilant about the construction of their next vessels. This is perhaps also why they took so long to send this replacement shuttle”, believes Alain Cirou.
For its part, the Russian agency excludes a manufacturing defect. According to a new press release published on Tuesday, the second leak also comes from an “external impact”. She also indicates having noted the presence of “holes” on the surface of the vessel. According to Roscosmos, a series of experiments designed to “imitate the damage” will still be carried out in order to understand the origin of the incidents, and to “parry this kind of threat”.
The ISS is one of the few fields of cooperation still underway between Moscow and Washington since the start of the Russian offensive in Ukraine, launched a year ago, and the international sanctions that followed. “It’s a bit like international co-ownership in space. Common systems, such as energy, resources and the means to get on and off the station are shared by astronauts, regardless of the situation on earth, explains the specialist again. It is therefore essential that everyone be reassured that Russia has mastered its equipment”.