Astronaut Jonny Kim Departs NASA to Resume Naval Career

A Transition from Space to Service

NASA astronaut Jonny Kim is departing the agency to continue his military career, according to statements from NASA and Space. The 42-year-old astronaut, who joined NASA in 2017, leaves on Aug. 27 after nine years with the agency. He is returning to active duty in the U.S. Navy, where he holds the rank of lieutenant commander, to complete the remainder of his military career within naval aviation training.

Kim's resume is remarkable even by astronaut standards. He is a physician with a medical degree from Harvard, a dual-designated naval aviator and flight surgeon, and a former Navy SEAL who served with SEAL Team Three. NASA officials said he participated in more than 100 combat operations as a medic, sniper, navigator, and point man, earning the Silver Star, Bronze Star with Combat 'V,' and numerous other commendations.

A Single Mission, A Lasting Impact

Kim's time at NASA included one spaceflight: a long-duration mission to the International Space Station (ISS) that launched in April 2025 aboard a Russian Soyuz spacecraft. He flew with cosmonauts Sergey Ryzhikov and Alexey Zubritsky, serving as a flight engineer during Expeditions 72 and 73. The trio spent 245 days in space, orbiting Earth 3,920 times and traveling nearly 104 million miles (167 million kilometers), as reported by both Space and space & defense.

During the mission, Kim served as the U.S. Operating Segment lead for the second half of Expedition 73, overseeing operations across the station's international modules, according to space & defense. He also commanded the Canadarm2 robotic arm during the first capture of Northrop Grumman's Cygnus XL spacecraft, which delivered 11,000 pounds of supplies. NASA noted that the station reached a milestone during his expedition when every docking port was occupied for the first time in 25 years, a detail also reported by space & defense.

Kim and his Roscosmos crewmates landed in Kazakhstan in December 2025, concluding the eight-month science mission. The mission contributed to research in technology development, Earth science, biology, and human health, according to space & defense.

A Career of Service

Kim's path to NASA began long before his astronaut selection. He enlisted in the U.S. Navy after graduating high school in 2002, trained as a hospital corpsman, and completed SEAL training. He holds a bachelor's degree in mathematics from the University of San Diego and a medical degree from Harvard Medical School, followed by medical and flight training that earned him designation as a naval aviator and flight surgeon.

NASA selected Kim as part of its 2017 astronaut class, the 22nd in the agency's history. He and his 11 fellow selectees nicknamed themselves "The Turtles," a detail reported by Space. After completing two years of training—which included station systems, Russian language, robotics, T-38 flight operations, geology, survival training, and spacewalk preparation—Kim served as a capsule communicator in Mission Control at Johnson Space Center. He also contributed to Artemis program development and served as increment lead for Expedition 65, according to NASA officials quoted by Space.

Reactions from NASA Leadership

Kim's departure drew praise from NASA officials. Vanessa Wyche, director of NASA's Johnson Space Center, said in a statement: "Jonny has been an integral part of the agency, and his immeasurable impact will be felt for generations to come. 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."

NASA Administrator Jared Isaacman, quoted by space & defense, echoed that sentiment: "Jonny Kim represents the very best of NASA, a person who continually pushed the boundaries of exploration while inspiring countless others. 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."

Kim expressed gratitude for his time at NASA in a personal statement reported by space & defense, reflecting on the honor of his service. He now returns to the Navy to complete his military career in naval aviation training, continuing a life defined by service to his country—first as a SEAL, then a physician, an astronaut, and now an aviator.