Soyuz spacecraft regularly bring crew home from the International Space Station (ISS), but the one that returned on Tuesday had three empty seats.
In what’s thought to be the first voyage of its kind, Soyuz MS-22 undocked from the space station without any crew and took two hours to reach its landing spot in Kazakhstan following an automated, parachute-assisted descent.
But there was a good reason why the capsule was empty of any crew, as this is the vehicle that suffered a significant coolant leak while docked at the ISS last December. A video shot at the time showed a large amount of liquid pouring from the spacecraft.
As a precautionary measure, it was deemed too risky to use the Soyuz capsule to bring home three crewmembers in case its interior heated up to a dangerous level as it entered Earth’s atmosphere at high speed.
But NASA’s Russian counterpart, Roscosmos, which operates the Soyuz spacecraft, was still keen to bring it to Earth as they’d like to examine it to try to determine what exactly caused the leak.
The current thinking is that the capsule may have been struck by a micrometeoroid while docked at the station, but the engineers’ analysis will hopefully give us a definitive answer.
So what happened to the three crewmembers who traveled to the ISS inside Soyuz MS-22 last September?
Well, NASA astronaut Frank Rubio and Roscosmos cosmonauts Sergey Prokopyev and Dmitri Petelin are still aboard the orbital outpost about 250 miles above Earth. While for several months they had no means of getting home, Roscosmos in February sent up an empty, replacement Soyuz capsule, which is now docked at the space station.
The incident has led to the trio’s mission being extended by a whole six months, with the three crewmembers now scheduled to return home aboard the Soyuz MS-23 in September instead of this month.