Nikolai Chub

Nikolai Aleksandrovich Chub was born in 1984 in Novocherkassk, in Russia's Rostov region. He trained as an engineer, graduating from the South-Russian State Technical University (the Novocherkassk Polytechnic Institute) in 2006, and worked in technical roles before pursuing a career in spaceflight. In 2012 he was selected as a candidate for the Roscosmos cosmonaut corps, and over the following decade he completed the extensive training regimen — spacecraft systems, spacewalk preparation, survival training, and mission-specific instruction — that precedes a first flight. He waited more than ten years between selection and launch, a long apprenticeship that is common among cosmonauts assigned to long-duration station missions.

Chub made his first spaceflight aboard Soyuz MS-24, launching on September 15, 2023 with veteran commander Oleg Kononenko and NASA astronaut Loral O'Hara. Assigned to Expedition 70 and Expedition 71, Chub and Kononenko had their stay extended into a full year in orbit to accommodate the crew rotation schedule, while O'Hara returned earlier on the same capsule that had carried them up. The two cosmonauts ultimately spent about 374 days aboard the International Space Station — at the time the longest single continuous spaceflight ever recorded, surpassing the previous single-mission benchmark of roughly 371 days. During the mission Chub performed spacewalks with Kononenko, working on the exterior of the station's Russian segment. Because of a spacecraft swap tied to a coolant leak on an earlier Soyuz, he and Kononenko returned to Earth aboard Soyuz MS-25 on September 23, 2024, together with NASA astronaut Tracy Caldwell Dyson.

Chub's debut mission immediately placed him among the record-holders of human spaceflight, as his roughly 374-day expedition set a new mark for the longest uninterrupted stay aboard the ISS. Enduring more than a year of microgravity demanded rigorous exercise and medical monitoring, and the mission contributed valuable data on the effects of very long spaceflights on the human body — research directly relevant to future missions to the Moon and Mars. Now an experienced flight veteran, Chub remains an active Roscosmos cosmonaut eligible for future station assignments, having transformed a decade of patient preparation into one of the standout endurance flights of the modern era.