Jonny Kim is leaving NASA after nine years to return to active duty with the U.S. Navy, the space agency announced on August 27. The 42-year-old astronaut, a former Navy SEAL and Harvard Medical School graduate, completed his first spaceflight in December 2025, spending eight months aboard the International Space Station before returning to Earth.
Kim was selected as an astronaut in 2017 and served as a flight engineer during his mission to the ISS, which he launched to aboard Russia’s Soyuz MS-27 spacecraft on April 8, 2025. During his eight-month expedition, he orbited Earth 3,920 times and traveled nearly 104 million miles, conducting science research in low-Earth orbit.
His departure marks a transition back to his military roots. Kim enlisted in the Navy in 2002 and served as a SEAL, completing more than 100 combat operations and earning the Silver Star and Bronze Star Medal with “V” device for valor. After his service as a special operator, he was commissioned as an officer in 2012 and pursued medical training, earning his doctorate from Harvard Medical School in 2016. While serving as an astronaut, he also qualified as a Naval Aviator in 2023, completing advanced helicopter training.
Kim’s decision to return to military service reflects a pattern among military-affiliated astronauts. In May 2026, NASA astronaut Andrew Morgan retired from the agency after 12 years to continue his service as an Army officer, having spent 272 days in space. Military personnel detailed to NASA remain on active-duty status for pay, benefits, and leave, allowing them to transition between roles within the broader federal service structure.
NASA Administrator Jared Isaacson praised Kim’s contributions, saying in a statement that “Jonny Kim represents the very best of NASA, a person who continually pushed the boundaries of exploration while inspiring countless others. We are grateful for his dedication to our nation and to the pursuit of knowledge, and we wish him success as he continues his service in the U.S. Navy.”
In his own statement, Kim reflected on his time at the agency: “Contributing to space exploration and serving NASA has been the honor of a lifetime. Throughout my career, I’ve learned that beyond the missions, the training, and the hardware, success always comes down to the people. They are our greatest asset, and leading with love and empathy is how we achieve the impossible.” He added that he looks forward to “carrying my commitment to service, my enduring love for space and technology, and the hard-earned lessons of this past decade into my next chapter to make a meaningful impact on humanity’s future.”
Sources
- Task & Purpose — Kim’s departure announcement, military background, and statement
- Space.com — Confirmation of Kim’s nine-year tenure at NASA and August 27, 2026 departure
- NASA — ISS mission details, launch date (April 8, 2025), return date (December 9, 2025), orbital statistics, and administrator statement
- NBC Los Angeles — Eight-month mission duration and 245-day spaceflight confirmation
