Astronaut Jonny Kim Leaves NASA to Return to Active Military Duty
The former Navy SEAL and flight surgeon departs the agency after nine years and a 245-day mission to the ISS.
Astronaut Jonny Kim departed NASA on August 27, 2026, ending a nine-year tenure with the agency. Kim is returning to active military duty to conclude his career within naval aviation training.
During his time at NASA, Kim completed a 245-day mission to the International Space Station (ISS), having launched in April 2025 and returned in December 2025 aboard a Russian Soyuz spacecraft. Beyond his time in orbit, Kim held critical leadership roles, serving as a CAPCOM and leading the astronaut crew operations branch, where he contributed to the development of the Artemis program. Reflecting on his departure, Kim stated that serving NASA and contributing to space exploration has been "the honor of a lifetime."
A Rare Multidisciplinary Career
Kim joined NASA as part of the 2017 astronaut class, known as "The Turtles." He entered the agency with a professional pedigree rarely seen in human spaceflight, combining elite special operations, aviation, and medicine. His military record includes service as a Navy SEAL, a naval aviator, and a flight surgeon, with a history of over 100 combat operations. Additionally, Kim holds a medical degree from Harvard, allowing him to bridge the gap between tactical military operations and complex medical research in microgravity.
Impact on Human Spaceflight
Kim's transition marks the end of a chapter where his diverse expertise was applied to the advancement of the Artemis program, which aims to return humans to the lunar surface. His ability to operate at the intersection of medicine and aviation provided NASA with a unique asset for crew operations and mission safety. Vanessa Wyche, director of NASA's Johnson Space Center, noted that Kim has been an integral part of the agency and that his "immeasurable impact will be felt for generations to come."
A Trend of Departures
Kim's exit is part of a broader shift within the astronaut corps in 2026. He is among several high-profile figures to leave the agency this year, including Mike Fincke and Canadian astronaut Jeremy Hansen. As NASA continues to scale the Artemis missions, the departure of experienced crew members like Kim highlights the ongoing rotation of personnel between government service, military duty, and the evolving needs of deep-space exploration. Observers will now watch how the agency fills the leadership void in the astronaut crew operations branch as it prepares for the next phase of lunar exploration.