NASA astronaut Sunita “Suni” Williams retired on December 27, 2025, closing a 27-year career that reshaped how long humans can live and work in orbit. Across three missions to the International Space Station (ISS), Williams spent 608 days in space, ranking second among NASA astronauts for total time off Earth, behind Peggy Whitson, who has spent 695 days. Williams leaves NASA after serving as a station commander, test pilot, spacewalker, and steady hand during one of the agency’s most difficult crewed missions.
“Anyone who knows me knows that space is my absolute favorite place to be,” said Williams to NASA. “It’s been an incredible honor to have served in the Astronaut Office and have had the opportunity to fly in space three times. I had an amazing 27-year career at NASA, and that is mainly because of all the wonderful love and support I’ve received from my colleagues.”
Born in 1965 in Euclid, Ohio, Williams grew up in Massachusetts in a family that valued science and discipline. Her father, a neuroanatomist from Gujarat, India, encouraged curiosity early. She later earned a degree in physical science from the U.S. Naval Academy and a master’s in engineering management from Florida Institute of Technology. Before joining NASA in 1998, she built a long Navy career, flew more than 40 aircraft types, and logged over 4,000 flight hours. That background shaped her calm approach to high-risk missions.
Williams first flew to the ISS in 2006 aboard Space Shuttle Discovery. During a 195-day stay, she completed four spacewalks and helped rewire the station’s power systems. She also became the first person to run a marathon in orbit, finishing the Boston Marathon on a treadmill while circling Earth.
Her second mission in 2012 marked a new chapter. Williams commanded the ISS, repaired a failing coolant system during spacewalks, and completed a full triathlon using onboard exercise gear. The mission showed how astronauts protect muscle and bone health during long stays in microgravity.
Her final flight, launched in 2024 on Boeing’s Starliner, tested that experience to the limit. The mission, planned as a short demonstration, stretched to 286 days after thruster failures and helium leaks delayed the spacecraft’s return. Williams and fellow astronaut Butch Wilmore joined the station crew, adjusted schedules, and kept operations stable. She commanded the ISS again and completed two more spacewalks, raising her career total to nine and setting a new record for women.
Williams also supported long-term research on fluid behavior and human health in orbit. That work continues to guide NASA’s plans for future Moon missions under Artemis. In retirement, she is expected to advise space programs and promote science education. Her career shows how preparation, adaptability, and teamwork keep human spaceflight moving forward.