# Soyuz MS-09

Soyuz MS-09 was a Soyuz spaceflight that launched on 6 June 2018. It transported three members of the Expedition 56/57 crew to the International Space Station (ISS). MS-09 is the 138th flight of a Soyuz spacecraft. The crew consisted of a Russian commander along with an American and a German flight engineer. The mission ended at 05:02 UTC on 20 December 2018.

## Crew

Prime crew :
| Position | Crew | Crew |
| Commander | Sergey Prokopyev, Roscosmos Expedition 56 / 57 First spaceflight | Sergey Prokopyev, Roscosmos Expedition 56 / 57 First spaceflight |
| Flight Engineer 1 | Alexander Gerst, ESA Expedition 56 Second spaceflight | Alexander Gerst, ESA Expedition 56 Second spaceflight |
| Flight Engineer 2 | Serena Auñón-Chancellor, NASA Expedition 56 Only spaceflight | Serena Auñón-Chancellor, NASA Expedition 56 Only spaceflight |
Backup crew :
| Position | Crew | Crew |
| Commander | Oleg Kononenko, Roscosmos | Oleg Kononenko, Roscosmos |
| Flight Engineer 1 | David Saint-Jacques, CSA | David Saint-Jacques, CSA |
| Flight Engineer 2 | Anne McClain, NASA | Anne McClain, NASA |

## Air leak

During the night of 29 August 2018, a small air leak in the ISS was noticed by ground control. A 2 mm (0.079 in) hole in the orbital module was discovered, later stated to have been "hidden with a low-quality patch job." Russian crew members used Kapton tape to temporarily seal the leak while a permanent fix was devised. The leak was successfully sealed with the use of a repair kit based on an epoxy sealant, and no further changes in air pressure were noted as of 31 August. On 4 September 2018, it was announced that the hole was created by a drill, but it was unclear if it was accidental or deliberate. Russian officials indicated the hole was some kind of sabotage, perhaps during the module's manufacturing process. Russian officials even speculated that one of the NASA crew members had drilled the hole.
On 11 December 2018, Kononenko and Prokopyev conducted an EVA, cutting into the thermal blankets and pulling away insulation, in order to examine the external hull, take images of the area and retrieve samples of residue to be used in the investigation. As the hole is in the orbital module that is jettisoned before re-entry, the return flight was not endangered. The return of the MS-09 crew was briefly delayed by the launch failure of Soyuz MS-10 (until the arrival of the next crew on MS-11). MS-09 landed on 20 December at about 05:03 UTC.
Further reports and investigations were enacted thereafter. Prokopyev was quoted as saying that the drill hole was made from the inside, however it is still unclear when it was made. In September 2019, the head of Roscosmos, Dmitry Rogozin, claimed that Roscosmos knows exactly what happened but that the agency would keep this information secret. On April 20, 2021, major Russian language tabloid Moskovskij Komsomolets published an article citing a Facebook post by Vadim Lukashevich which claimed that the hole was drilled by Serena Auñón-Chancellor, after a blood clot developed in her jugular vein, which was disputed by NASA and called "preposterous" by Ars Technica. The full treatment was published in 2020, documented in the correspondence paper "Venous Thrombosis during Spaceflight" by NEJM. The results of a Roscosmos investigation were later handed over to “law enforcement authorities” in late 2021, with a new theory being promoted by state media: that the hole is “due to suffering [psychologically] after a failed romantic relationship with one of the crew members.”