SpaceX may have to come to the rescue of the stranded ISS crew if the Russian plan fails

The Soyuz might still be used to return the trio home if safety inspections are successful. As an alternative, Roscosmos might be able to deliver them to the ISS in an empty Soyuz.

However, NASA might intervene if Roscosmos finds its options inadequate.

On Thursday, it was revealed that the American space agency had talked to SpaceX about the possibility of sending Rubio, Prokopyev, and Petelin back to Earth in one of SpaceX's Crew Dragon spacecraft.

NASA spokeswoman Sandra Jones told Reuters, "We have asked SpaceX a few questions on their capability to return additional crew members on Dragon if necessary, but that is not our prime focus at this time."

It's unclear if NASA's investigation is focused on adding more seats to the Crew Dragon spacecraft currently docked at the International Space Station (ISS).

The spaceship with four Crew-5 members on board arrived at the orbital outpost in October. It won't leave again until March. It's also plausible that NASA wants SpaceX to launch an empty Crew Dragon to the International Space Station to rescue the three crew members.

Yury Borisov, the head of Roscosmos, stated last week that the organization has "no reservations" regarding the crew's safety.

However, suppose all seven crew members need to evacuate. In that case, the ISS currently only has one emergency escape path (the docked Crew Dragon), and both NASA and Roscosmos will want to find a solution as quickly as feasible.

The cause of the leak is still unclear

NASA and Roscosmos are looking into three potential origins of the leak: a rupture from a meteorite, a hit from space junk, or a hardware issue with the Soyuz spacecraft itself.

According to Mike Suffredini, who oversaw NASA's ISS program from 2007 until 2015, a hardware issue might cause Roscosmos to question the reliability of other Soyuz vessels, including the one it might deploy for the crew's rescue.

"I can assure you that's something they're looking at, to see what's back there and whether there's a concern for it," he said. "The thing about the Russians is they're really good at not talking about what they're doing, but they're very thorough," reports Reuters.

Engineers would determine by Tuesday how to bring the crew back to Earth, according to Roscosmos chief Yuri Borisov, but the organization said that day that it would make that decision in January.

The crew compartment of the spacecraft is currently vented with airflow permitted through an open hatch to the ISS. According to an earlier NASA statement, the temperatures there are still "below safe norms."

Sergei Krikalev, the head of Russia's crewed space projects, warned reporters last week that the temperature would rise quickly if the hatch to the station were closed.

According to Jones, NASA and Roscosmos mainly concentrate on pinpointing the source of the leak and monitoring the condition of MS-22, which is also intended to act as the three-person crew's lifeboat if an emergency on the station necessitates evacuation.

The leak was facing the wrong way for a micrometeoroid strike to be the cause, NASA's ISS program manager Joel Montalbano told reporters last week, though a space rock could have come from another direction. A recent meteor shower initially seemed to increase the odds of a micrometeoroid strike as the culprit.

And if space debris is to blame, it would increase worries about an increasingly cluttered orbital environment and prompt inquiries about whether such crucial equipment as the spacecraft's coolant line should have been shielded from junk, as other elements of the MS-22 spacecraft are.

"We are not shielded against everything throughout the space station," Suffredini said. "We can't shield against everything."