Mike Fincke, a NASA astronaut and former Air Force colonel, announced his retirement from the agency on August 12, 2026 after 30 years of service. Fincke was selected as part of NASA's 1996 astronaut class, the 16th group, and has flown to space four times on three different vehicles: two Soyuz launches, one Space Shuttle Endeavour mission, and one SpaceX Dragon flight. During his career he served as commander of the International Space Station on two occasions, first from October 22, 2008, to April 2, 2009, during Expedition 18, and again from December 7, 2025, to January 12, 2026, during Expedition 74. Fincke spent much of his later career supporting the Commercial Crew Program. He previously led the Astronaut Office's Commercial Crew Branch and, in January 2019, was assigned as a crew member for the Boeing CST-100 Starliner Flight Test, later serving as backup pilot and training with NASA astronaut Scott Tingle, CSA astronaut Joshua Kutryk, and JAXA astronaut Kimiya Yui for the Starliner‑1 mission. After the 2024 Flight Test, which carried NASA astronauts Butch Wilmore and Sunita Williams, Fincke and Yui were reassigned to the SpaceX Crew‑11 mission, launching on August 1, 2025 with NASA astronaut Zena Cardman and Roscosmos cosmonaut Oleg Platonov for a 166‑day stay aboard the ISS. During that mission Fincke experienced a brief medical episode on January 7, 2026 in which he lost speech for about 20 minutes while eating dinner; NASA did not disclose the cause, and Fincke later described the event as sudden and brief to the Associated Press. His departure follows the retirements of fellow Starliner trainees Butch Wilmore and Sunita Williams in 2025 and 2026, respectively, as well as Josh Cassada in October 2024 and Jeanette Epps in June 2025, leaving fewer astronauts with direct Starliner experience. NASA officials said the agency continues to develop crew assignments for Starliner, noting that a crewed mission may be scheduled after the uncrewed Starliner‑1 flight, the timing of which remains under review. Fincke expressed gratitude to his crewmates, ground teams, international partners and families, and said he will continue to support exploration efforts and help train the next generation of engineers and leaders. NASA has indicated it remains prepared to conduct crewed Starliner missions when assignments are finalized.