Aleksandr Avdeyev (pilot)

Aleksandr Sergeyevich Avdeyev (born April 11, 1975) is a Russian cosmonaut in the Roscosmos cosmonaut corps.

Avdeyev was selected as a cosmonaut on October 11, 2010. He completed his basic cosmonaut training in July 2012 and was qualified as a test cosmonaut.

He served as a flight engineer on Expedition 67/68 to the International Space Station (ISS). Avdeyev launched to the ISS aboard Soyuz MS-22 on September 21, 2022, alongside Sergey Prokopyev and Dmitri Petelin. Due to a coolant leak in Soyuz MS-22, they returned to Earth aboard Soyuz MS-23 on September 27, 2023, after spending 370 days in space. This duration classifies Avdeyev as a long-duration spaceflight participant.

During his time on the ISS, Avdeyev participated in numerous scientific experiments and performed spacewalks. His work contributed to research in areas such as biology, medicine, and materials science.