Russia is considering a “rescue” plan to send an empty spacecraft to the International Space Station (ISS) to bring home three stranded crew members after their Soyuz crew capsule sprang a leak while docked to the orbiting outpost.
Roscosmos and Nasa officials said at a news conference on Thursday they were continuing to investigate how the coolant line of the capsule’s external radiator sustained a tiny puncture last week, just as two cosmonauts were preparing for a routine spacewalk.
The vehicle, known as MS-22, began spraying its coolant into space on 14 December, with dramatic Nasa TV images showing white particles resembling snowflakes streaming out of the rear.
Sergei Krikalev, who leads human spaceflight programs at Russia’s Roscosmos, said the damage was being assessed.
No final decision has been made about the precise means of flying the capsule’s crew members back to Earth – whether by launching another Soyuz to retrieve them or by the seemingly less likely option of sending them home in the leaky capsule without most of its coolant.
If a thermal analysis – which assesses how hot it will get inside the cabin – concludes MS-22 is unfit for crewed flight, then a scheduled launch of another Soyuz capsule in mid-March from Baikonur Cosmodrome could be moved up and it would launch un-crewed, Krikalev said.
“They’re looking at late February to send up the next Soyuz vehicle,” added Joel Montalbano, Nasa’s ISS program manager, who was also on the call.
If that were the case, the damaged spaceship would return to Earth without crew.
It is not the first leak on the Soyuz. In 2018 the module sprang an air leak, which Roscosmos said might have been sabotage. Astronauts used tape to seal the leak after it caused a small loss of pressure that was not life-threatening.
MS-22 flew Russian cosmonauts Dmitry Petelin and Sergey Prokopyev, as well as Nasa astronaut Frank Rubio, to the ISS in September.
There are currently seven people aboard the orbital outpost, but if MS-22 were deemed unfit, it would also mean the ISS has just one “lifeboat” capable of carrying four people, in case it needs to be evacuated.
Americans Josh Cassada and Nicole Mann, Japan’s Koichi Wakata and Russia’s Anna Kikina arrived on a SpaceX Crew Dragon in October.
The cause of the damage still remained unclear, said Montalbano. But it did not appear as though the Geminid meteor shower – an annual phenomenon – was to blame, since the hull was penetrated from a different direction.
“Both the trajectory team in Houston and the trajectory team in Moscow confirmed it was not from the meteor showers,” Montalbano said.
More work was still needed to determine if it was caused by naturally occurring micrometeoroids, man-made debris in orbit, or a hardware failure, he added.
The Roscosmos chief, Yury Borisov, maintained that officials held no fears for the safety of the crew in a live broadcast on the Rossiya-24 TV channel on Wednesday.
“The temperature [on the Soyuz MS-22 spacecraft] has stabilised and has not exceeded 30C lately. Today, we have no fears, primarily about the life of the crew on the ISS,” he said. “The temperature has stabilised after we brought in air ducts there from the Russian segment and are maintaining the temperature regime by ventilators.”
A spacewalk to upgrade the station’s solar arrays that was postponed on Wednesday took place on Thursday.
Reuters and Agence France-Presse contributed to this report