# Soyuz MS-23

Soyuz MS-23 was an uncrewed Russian Soyuz spaceflight that launched from Baikonur on 24 February 2023 to the International Space Station to replace the damaged Soyuz MS-22 spacecraft for landing that NASA astronaut Francisco Rubio and Roscosmos cosmonauts Sergey Prokopyev and Dmitry Petelin launched onboard on 21 September 2022 and had a coolant leak on 14 December before returning to Earth uncrewed on 28 March 2023.

## Background

Due to the 0.8 mm (0.031 in)-diameter hole punctured in the radiator of Soyuz MS-22 due to micro-meteoroid impact, there were doubts over the safety of Soyuz MS-22. So it was returned uncrewed like Soyuz 32, and MS-23 was launched uncrewed like Soyuz 34 as a replacement. As it was launched uncrewed, it carried ~430 kg (950 lb) dry cargo and equipment in its pressurized section, like a Progress MS spacecraft.
Until the replacement MS-23 docked with the ISS, SpaceX Crew-5 was considered among the options to return the MS-22 crew in case of emergency. This is due to the fact that SpaceX originally designed the Crew Dragon to host a crew of seven at a time. Due to these reasons, the International Space Station mission management team decided to move NASA astronaut Francisco Rubio's Soyuz seat liner from the Soyuz MS-22 spacecraft to Dragon Endurance to provide lifeboat capabilities in the event Rubio would need to return to Earth because of an emergency evacuation from the space station. The seat liner was moved on 17 January 2023, with installation and configuration continuing through most of the day, 18 January 2023. This seat liner swapping is not new between two Soyuz, but this was the first time swapping from Soyuz to Crew Dragon. The change allowed for increased crew protection by reducing the heat load inside the MS-22 spacecraft for cosmonauts Prokopyev and Petelin in the event of an emergency return to Earth. Alongside SpaceX Crew-6 space capsule is designed to bring back crew serving as an emergency evacuation after Crew-5.
As Soyuz MS-22 was unable to perform crew return, it reentered uncrewed like Soyuz 32, and MS-23 was launched empty like Soyuz 34 to return the crew. The original crewed mission was delayed and reassigned to the MS-24 mission.
As the MS-23 arrived at the space station on 26 February, Rubio's seat liner was transferred to the new Soyuz on 6 March, and the seat liners for Sergey Prokopyev and Dmitry Petelin were moved from MS-22 to MS-23 on 2 March ahead of their return in the Soyuz.

## Crew

| Position | Launching crew | Landing crew |
| Commander | None | Sergey Prokopyev, Roscosmos Expedition 67/68/69 Second spaceflight |
| Flight Engineer | None | Dmitry Petelin, Roscosmos Expedition 67/68/69 First spaceflight |
| Flight Engineer | None | Francisco Rubio, NASA Expedition 67/68/69 First spaceflight |

### Original crew

| Position | Crew member | Crew member |
| Commander | Oleg Kononenko, Roscosmos | Oleg Kononenko, Roscosmos |
| Flight Engineer | Nikolai Chub, Roscosmos | Nikolai Chub, Roscosmos |
| Flight Engineer | Loral O'Hara, NASA | Loral O'Hara, NASA |

### Backup crew

| Position | Crew member | Crew member |
| Commander | Aleksey Ovchinin, Roscosmos | Aleksey Ovchinin, Roscosmos |
| Flight Engineer | Tracy Caldwell Dyson, NASA | Tracy Caldwell Dyson, NASA |