Washington: NASA astronaut Sunita Williams has retired after a distinguished 27-year career with the US space agency, with her retirement taking effect on December 27, 2025. Williams exits NASA as one of the most accomplished astronauts in human spaceflight history, having played a key role in shaping the future of low Earth orbit missions and deep-space exploration.
Over the course of three long-duration missions aboard the International Space Station (ISS), Williams spent a total of 608 days in space, the second-highest cumulative spaceflight time by any NASA astronaut. Her career included service as a flight engineer and later as commander of the space station, underlining her leadership role in some of NASA’s most complex missions.
NASA Administrator Jared Isaacman praised Williams as a pioneer whose contributions laid critical groundwork for future exploration. He said her leadership aboard the ISS and her role in advancing commercial crew missions have helped prepare NASA for Artemis missions to the Moon and eventual human journeys to Mars.
Williams also set multiple spacewalk records. She completed nine spacewalks totaling 62 hours and 6 minutes, making her the woman with the highest cumulative spacewalk time and placing her fourth overall in the all-time rankings. She also earned global recognition as the first person to run a marathon in space.
Her first spaceflight came in December 2006 aboard space shuttle Discovery during the STS-116 mission. She returned to Earth with the STS-117 crew and, during Expeditions 14 and 15, completed a then-record four spacewalks. In 2012, she launched from Kazakhstan for Expedition 32/33, later assuming command of the ISS during Expedition 33. That mission included critical repair spacewalks addressing a coolant leak and replacing power system components.
Williams’ most recent mission began in June 2024, when she launched aboard Boeing’s Starliner spacecraft as part of NASA’s Crew Flight Test. She later joined Expeditions 71 and 72 and once again commanded the ISS. After completing two additional spacewalks, she returned to Earth in March 2025 aboard SpaceX’s Crew-9 mission.
Vanessa Wyche, Director of NASA’s Johnson Space Center, described Williams as a trailblazing leader whose dedication and technical excellence will inspire future generations of explorers. Scott Tingle, Chief of the Astronaut Office, called her an exceptional colleague whose influence on the astronaut corps will be deeply missed.
Beyond spaceflight, Williams held several key roles within NASA. She participated in the NEEMO underwater mission in 2002, served as deputy chief of the Astronaut Office, and later worked as Director of Operations in Star City, Russia. In her final years at NASA, she contributed to the development of helicopter-based training systems designed to prepare astronauts for future lunar landings.
A native of Needham, Massachusetts, Williams is a graduate of the US Naval Academy and holds a master’s degree in engineering management from the Florida Institute of Technology. A retired US Navy captain, she has logged more than 4,000 flight hours across 40 aircraft types.
Reflecting on her career, Williams said serving in the Astronaut Office and flying in space three times had been the honor of her life. She added that the ISS and the people behind it have made the next era of exploration to the Moon and Mars possible, and expressed excitement about watching NASA’s future missions unfold.
