Fincke was selected by
NASA in April 1996 to be an astronaut. He reported to the
Johnson Space Center in August 1996. Having completed two years of training and evaluation, he was assigned technical duties in the Astronaut Office Station Operations Branch serving as an International Space Station spacecraft communicator (ISS CAPCOM), a member of the Crew Test Support Team in Russia and as the ISS crew procedures team lead. training in
Sardinia, alongside
Soichi Noguchi,
Andreas Mogensen,
Nikolai Tikhonov,
Andrew Feustel, and
David Saint-Jacques.
Expedition 9 exam on Fincke during Expedition 9 Fincke was the space station science officer and flight engineer for ISS
Expedition 9 from April 18 through October 23, 2004. The mission was launched from the
Baikonur Cosmodrome in
Kazakhstan aboard the
Soyuz TMA-4 spacecraft and docked with the International Space Station on April 21, 2004. Fincke spent six months aboard the ISS continuing ISS science operations, maintaining station systems, and performing four spacewalks. Expedition 9 concluded with undocking from the station and safe landing back in Kazakhstan on October 23, 2004. Fincke completed his first mission in 187 days, 21 hours, and 17 minutes, and logged a total of 15 hours, 45 minutes, and 22 seconds of
EVA time in four spacewalks. Fincke was commander of
Expedition 18. He arrived at the International Space Station aboard the
Soyuz TMA-13 on October 14, 2008 with cosmonaut
Yuri Lonchakov and
space flight participant Richard Garriott. While Richard Garriott was aboard, Fincke participated during his personal time (along with Yury Lonchakov,
Gregory Chamitoff, and Richard Garriott) in filming and starring in a science-fiction movie made in space,
Apogee of Fear. On April 8, 2009, Fincke, Lonchakov, and space tourist
Charles Simonyi returned to Earth aboard the TMA-13. Replacing Fincke as commander of the space station was
Gennady Padalka, whom he served with on Expedition 9.
STS-134 Fincke was a
mission specialist on
STS-134, which was his only flight on the
Space Shuttle. Fincke made three spacewalks during the mission. He completed 26 hours and 12 minutes of spacewalking time, bringing his total EVA time to 48 hours and 37 minutes. However, in June 2022, NASA revised the mission to a two-person flight test with Fincke serving as the backup spacecraft test pilot. On September 30, 2022, NASA announced that Fincke would fly as the pilot on the Starliner's first operational mission,
Boeing Starliner-1 (PCM-1). However, in March 2025, he was announced as the pilot of
SpaceX Crew-11 due to testing with the following technical issues during the
Boeing Crew Flight Test. Fincke has been certified as a co-pilot/flight engineer for the Soyuz, a mission specialist for the flight deck crew of the Space Shuttle, and a pilot for Starliner and Crew Dragon. His extensive work in spacecraft development included significant contributions to Starliner's development through his work in the Avionics and Software Integration Lab (ASIL), focusing on flight software refinement, systems integration, and human-spacecraft interfaces. Throughout his career, Fincke has remained at the forefront of testing and developing human-rated spacecraft, leveraging his engineering, flight test, and astronaut experience to contribute to the next era of space exploration. On August 1, 2025, Fincke launched on NASA's
SpaceX Crew-11 mission to the International Space Station, where he served as a member of
Expedition 73/
74.
Medical incident and early return On January 7, 2026, Fincke experienced an undisclosed "medical situation" that prompted NASA to shorten the mission. The incident led to the cancellation of two planned
spacewalks on January 8 and 15, including preparations for installation of
ISS Roll-Out Solar Arrays (iROSAs) and other maintenance tasks on the
Harmony module and the station’s S6 and S4 truss. At a news conference on January 8, 2026, NASA administrator
Jared Isaacman announced that Crew-11 would return to Earth earlier than planned due to the medical situation. Crew-11 ultimately splashed down on January 15, 2026 about a month earlier than planned. In a statement on February 25, 2026, Fincke revealed that he experienced the medical event. He said that the event required immediate attention from his crewmates, and thanks to their actions under the guidance of NASA
flight surgeons, he was quickly stabilized. He said that the decision to return home early was driven by a desire to take advantage of advanced
medical imaging not available on the space station. After splashdown, Fincke was treated at
Scripps Memorial Hospital La Jolla and stated that he is subsequently doing "very well". == Acting ==