Navy SEAL, Harvard Doctor, Astronaut... 'Ultimate Model Son' Johnny Kim Leaves NASA After 10 Years

Over 100 Combat Missions in Iraq and a Harvard Medical School Graduate
Leaving NASA to Return to Active Duty in the U.S. Navy
Continuing His Military Career in Naval Aviation Training

Korean-American astronaut Johnny Kim (42), who served as a U.S. Navy SEAL, graduated from Harvard Medical School, worked as a doctor and naval aviator, and even traveled to space, is leaving the National Aeronautics and Space Administration (NASA) after approximately 10 years.

On August 28, Yonhap News, citing NASA, reported that Johnny Kim would complete his service at NASA as of this day and return to active duty in the U.S. Navy. Kim, who holds the rank of Lieutenant Commander, plans to continue his remaining military career in the field of naval aviation training.

Korean American astronaut Johnny Kim, 42, who has served as a Navy SEAL, graduated from Harvard Medical School, worked as a physician and naval aviator, and traveled to space, is leaving the National Aeronautics and Space Administration (NASA), where he spent about 10 years. Johnny Kim Instagram

It has been nine years since he was selected as a NASA astronaut. Last year, Kim returned to Earth after completing a 245-day assignment on the International Space Station (ISS). Born in 1984 in Los Angeles, California, to Korean immigrant parents, Kim is often described in the United States as having an “unreal” career. His first choice was not college, but the military.

After graduating high school in 2002, Kim enlisted in the Navy and completed medical corpsman training as well as Basic Underwater Demolition/SEAL (BUD/S) training to be assigned to SEAL Team 3. He later served in the Iraq War, carrying out over 100 combat operations as a medic, sniper, navigator, and pointman. For his service, he received the Silver Star and the Bronze Star Medal with combat “V” device. After witnessing the injuries and deaths of comrades on the battlefield, he decided to pursue medicine.

100 Combat Missions in Iraq, Harvard Medical School, and Even Space

Through the Navy’s enlisted-to-officer transition program, Kim majored in mathematics at the University of San Diego and graduated with highest honors, later enrolling in Harvard Medical School to earn an M.D. degree. He also completed an internship in emergency medicine at Massachusetts General Hospital and Brigham and Women’s Hospital, both affiliated with Harvard. Even after becoming a doctor, his journey of challenges continued. In 2017, Kim applied for NASA’s astronaut candidate program. At that time, NASA received about 18,300 applications—the most in its history—and only 12 candidates, including Kim, were selected.

He majored in mathematics at the University of San Diego through the Navy’s enlisted-to-officer program, graduating with highest honors, and then went on to Harvard Medical School where he received his Doctor of Medicine (M.D.) degree. Kim applied for NASA's astronaut candidate recruitment in 2017. At that time, NASA received a record number of over 18,300 applicants, of whom only 12 were ultimately selected as final candidates. Johnny Kim Instagram

After about two years of training in ISS systems, robotics, Russian language, T-38 jet operations, survival training, and spacewalks, he qualified as a full astronaut in 2020. That astronaut class was trained for possible future assignments to the ISS, the Artemis lunar program, and Mars exploration. While working at NASA, Kim maintained his Navy career, undergoing flight and aerospace medicine training to become a dual-designated naval aviator and flight surgeon.

Then, last year, he finally went to space. On April 8, 2025, Kim arrived at the ISS aboard the Soyuz MS-27 spacecraft with Russian astronauts Sergei Rizikov and Alexei Zubritsky. As flight engineer for Expeditions 72 and 73, he spent 245 days in space, conducting scientific research and various technology demonstrations, before returning to Kazakhstan on December 9 of the same year.

During that 245-day period, Kim orbited the Earth 3,920 times. His total travel distance was approximately 104 million miles (about 167 million km). While on the ISS, he participated in life sciences, human biology, Earth science, and technology experiments for future space exploration. In the latter part of Expedition 73, he was responsible for overseeing the U.S. operations segment, and he personally operated the Canadarm2 robotic arm to capture Northrop Grumman’s new Cygnus XL cargo spacecraft and attach it to the ISS.

'Korean-American' Johnny Kim Eating Kimchi in Space... NASA Says 'Inspired Countless People'

Kim’s identity as a Korean-American also attracted attention during his time in space. He shared that during Thanksgiving on the ISS, he ate kimchi, cooked rice, and seaweed sent by his family. After returning to Earth, he mentioned kimchi, rice, and seaweed as the foods he missed most in a NASA interview, saying, "It’s food I’ve eaten since childhood."

Kim arrived at the ISS on April 8, 2025, aboard the Soyuz MS-27 spacecraft with Russian astronauts Sergey Rizikov and Alexey Zubritski. Johnny Kim Instagram

NASA highlighted Kim’s achievements as it announced his retirement. Jared Isaacman, a NASA director, stated, "Johnny Kim represents the very best NASA has to offer," adding, "He has consistently pushed the boundaries of exploration and inspired countless people." Isaacman also remarked that Kim’s research on the ISS "contributed to critical scientific advancements that will shape NASA’s future missions for decades to come." Johnny Kim also looked back on his nearly 10 years with NASA.

He said, "It was a lifelong honor to contribute to space exploration and serve at NASA," and "What I have learned through my career is that what ultimately determines success is not the mission, the training, or the equipment, but people." He continued, "People are our greatest asset, and leading with love and empathy is how we turn the impossible into possible. I hope to take my unwavering love for space and technology, and the lessons of the past ten years, into my next journey to make a meaningful impact on humanity’s future."

Having transformed from a Navy SEAL to a doctor, then again to a naval aviator and astronaut, Kim’s next chapter will once again be with the U.S. Navy. NASA stated that Kim is scheduled to complete his remaining military service in the field of naval aviation training.

This content was produced with the assistance of AI translation services.