Preparations are under way to bring back three astronauts who have been on the International Space Station for nearly a year – six months longer than expected.
A rescue craft sent by Russian space agency Roscosmos earlier this year is due to leave the ISS on September 27, with Nasa astronaut Frank Rubio and Russian cosmonauts Dmitry Petelin and Sergey Prokopyev on board.
A crew member for part of their time on the ISS has been UAE astronaut Sultan Al Neyadi, who arrived in March on the Arab world's longest space mission.
The American and two Russians travelled to the ISS on September 21, 2022. But three months after docking, their Soyuz MS-22 spacecraft suffered catastrophic damage – reportedly from a meteor strike.
Now rescue craft Soyuz MS-23, which arrived uncrewed at the ISS in February with 430kg of supplies, is undergoing preparations for the journey back to Earth for the three astronauts.
How are they coming back?
Nasa said that one of two manoeuvres was made on Friday, so that Soyuz MS-23 can undock successfully from the ISS.
This will help ensure the correct trajectory for the journey home, while also making arrangement for the arrival of the Soyuz MS-24 spacecraft – a planned Russian crewed mission, set to travel to the space station in September.
“The Northrop Grumman Cygnus cargo spacecraft’s delta velocity thruster fired at 10.35am EDT Friday for 22 minutes, 48 seconds in a reboost of the International Space Station,” Nasa said on Friday.
“It was one of two scheduled reboosts to target the proper trajectory for the Roscosmos Soyuz MS-24 launch and two-orbit rendezvous to the orbiting complex on September 15, as well as the Soyuz MS-23 undocking and landing on September 27.”
The three returning astronauts are set to land in Kazakhstan, with the exact time to be announced closer to date.
What happened to the damaged spacecraft?
Roscosmos said Soyuz MS-22 was possibly damaged by a micrometeorite that made a tiny hole in the spacecraft, causing a coolant leak that was beyond repair.
It would not have been able to maintain a stable temperature for astronauts during their journey home.
Russia brought Soyuz MS-22 back to Earth in autonomous mode in March.
In February, a cargo spacecraft, Progress MS-21, suffered a similar coolant leak, which was also blamed on “external factors”.
A record time in space
The extra six months means a record time spent by an American astronaut in space will be set.
Mr Rubio will beat the record of Mark Vande Hei, who spent 355 consecutive days on the ISS from 2020 to 2021.
Anton Shkaplerov and Pyotr Dubrov, who were on the same mission as Mr Hei, set a record time for Russians on the ISS. Mr Petelin and Mr Prokopyev are set to beat that.
Russian cosmonaut Valery Polyakov, who died last year, holds the world record for the longest single stay in space. He spent 437 days on the Mir space station.
How are stranded astronauts spending their time?
The three men have been busy carrying out duties that would have been assigned to the crew that was meant to replace them.
These include doing maintenance work, carrying out spacewalks, outreach activities and science investigations.
On board Soyuz MS-24 will be Nasa astronaut Loral O'Hara and cosmonauts Oleg Kononenko and Nikolai Chub.
The UAE's Dr Al Neyadi is due to return to Earth this month on a SpaceX Dragon craft.
