After nearly a decade of service to NASA, including an eight-month science expedition aboard the International Space Station, astronaut Jonny Kim’s last day at the agency is Thursday. He will continue serving as lieutenant commander in the U.S. Navy.

Kim launched to the space station in April 2025 aboard the Soyuz MS‑27 spacecraft to conduct scientific research as a flight engineer during Expeditions 72/73. During the mission, he orbited Earth 3,920 times, traveled nearly 104 million miles, and contributed to a broad range of scientific investigations spanning technology development, Earth science, biology, and human research critical for future exploration.

“Jonny Kim represents the very best of NASA, a person who continually pushed the boundaries of exploration while inspiring countless others,” said NASA Administrator Jared Isaacman. “His contributions aboard the International Space Station advanced critical science that will shape NASA’s future missions for decades to come. 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.”

Serving as the U.S. Operating Segment lead for the second half of Expedition 73, Kim oversaw operations across the station’s international modules. During the expedition, the station achieved a historic milestone when every available docking port was occupied for the first time in 25 years. He also commanded the Canadarm2 robotic arm during the first capture of Northrop Grumman’s new Cygnus XL spacecraft, securing 11,000 pounds of supplies for the station. Kim and his Roscosmos crewmates landed safely in Kazakhstan in December 2025.

“Jonny has been an integral part of the agency, and his immeasurable impact will be felt for generations to come,” said Vanessa Wyche, director of NASA’s Johnson Space Center in Houston. “From advancing groundbreaking science to inspiring the next generation, Jonny has been an incredible source of inspiration to our nation. His exceptional talent, determination, and grit will leave a lasting legacy at NASA.”

Kim was selected as a NASA astronaut in 2017 and completed two years of astronaut candidate training, which included instruction in space station systems, Russian language, robotics, T‑38 flight operations, geology, survival training, and spacewalk preparation.

He later supported station operations as a capsule communicator, or capcom, in NASA’s Mission Control Center at Johnson. Kim also contributed to Artemis program development through his work in the astronaut exploration branch, leading the astronaut crew operations branch, and serving as increment lead for Expedition 65. His experiences as a Navy SEAL, physician, and naval aviator provided unique perspectives in mission operations and crew support.

“Jonny approached every assignment with humility, precision, and steadfast commitment to the mission,” said Scott Tingle, chief of the Astronaut Office at NASA Johnson. “His combination of medical training, operational experience, and engineering insight strengthened our team and contributed to advancements in exploration and space station operations.”

Born in Los Angeles, Kim enlisted in the U.S. Navy after graduating high school in 2002. He trained as a hospital corpsman and completed Basic Underwater Demolition/SEAL training before joining SEAL Team Three. Over the course of more than 100 combat operations, he served as a medic, sniper, navigator, and point man, earning the Silver Star, Bronze Star with Combat “V,” and numerous additional commendations.

He earned a bachelor’s degree in mathematics from the University of San Diego and a doctor of medicine from Harvard Medical School. He completed his internship at Massachusetts General Hospital and Brigham and Women’s Hospital in Boston. Kim became a dual-designated naval aviator and flight surgeon, completing flight training at Naval Air Stations Corpus Christi in Texas and Whiting Field in Florida, and aerospace medical training at the Naval Aerospace Medical Institute at Naval Air Station Pensacola.

Kim is returning to active duty to finish out the remainder of his military career within naval aviation training.

“Contributing to space exploration and serving NASA has been the honor of a lifetime,” said Kim. “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. I look 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.”

To learn more about NASA’s astronauts and human space exploration, visit:

https://www.nasa.gov/astronauts

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Jimi Russell
Headquarters, Washington
202-358-1100
james.j.russell@nasa.gov

Anna Schneider
Johnson Space Center, Houston
281-483-5111
anna.c.schneider@nasa.gov