NASA astronaut Sunita Williams has retired after a distinguished 27-year career, with her retirement taking effect on December 27, 2025.
Over the course of three missions aboard the International Space Station (ISS), Williams established herself as one of the most accomplished astronauts in NASA’s history. She logged a total of 608 days in space, the second-highest cumulative time recorded by a NASA astronaut. She also ranks sixth among Americans for the longest single spaceflight, tied with astronaut Butch Wilmore, with both spending 286 days in orbit during NASA’s Boeing Starliner and SpaceX Crew-9 missions.
“Suni Williams has been a trailblazer in human spaceflight, shaping the future of exploration through her leadership aboard the space station and paving the way for commercial missions to low Earth orbit,” NASA Administrator Jared Isaacman said.
“Her work advancing science and technology has laid the foundation for Artemis missions to the Moon and advancing toward Mars, and her extraordinary achievements will continue to inspire generations to dream big and push the boundaries of what’s possible. Congratulations on your well-deserved retirement, and thank you for your service to NASA and our nation,” NASA said in a statement.
Williams also made history during spacewalks, completing nine extravehicular activities totalling 62 hours and 6 minutes. This stands as the most spacewalk time by a woman and the fourth-highest cumulative spacewalk duration overall. She was also the first person to run a marathon while in space.
“Over the course of Suni’s impressive career trajectory, she has been a pioneering leader,” said Vanessa Wyche, Director of NASA’s Johnson Space Center in Houston. “From her indelible contributions and achievements to the space station, to her groundbreaking test flight role during the Boeing Starliner mission, her exceptional dedication to the mission will inspire the future generations of explorers.”
Williams first flew into space in December 2006 aboard space shuttle Discovery on the STS-116 mission and returned with the STS-117 crew aboard space shuttle Atlantis. She served as a flight engineer for Expeditions 14 and 15 and completed a then-record four spacewalks during that mission.
In 2012, she launched from the Baikonur Cosmodrome in Kazakhstan for a 127-day stay on the ISS as part of Expeditions 32 and 33. During Expedition 33, she served as space station commander and carried out three spacewalks to repair a leak in a station radiator and replace a key power system component, NASA said.
Her most recent mission came in June 2024, when Williams and Wilmore launched aboard the Starliner spacecraft as part of NASA’s Boeing Crew Flight Test. The pair later joined Expeditions 71 and 72, with Williams once again assuming command of the space station during Expedition 72. She completed two spacewalks on the mission and returned to Earth in March 2025 as part of the SpaceX Crew-9 mission.
“Suni is incredibly sharp, and an all-around great friend and colleague,” said Scott Tingle, chief of the Astronaut Office at NASA Johnson. “She’s inspired so many people, including myself and other astronauts in the corps. We’re all going to miss her greatly and wish her nothing but the best.”
Beyond her time in orbit, Williams held several key leadership and training roles at NASA. In 2002, she participated in the NASA Extreme Environments Mission Operations (NEEMO), spending nine days living and working in an underwater habitat. After her first spaceflight, she served as deputy chief of NASA’s Astronaut Office and later became Director of Operations in Star City, Russia, following her second ISS mission. Most recently, she helped establish a helicopter training platform designed to prepare astronauts for future Moon landings.
A native of Needham, Massachusetts, Williams earned a bachelor’s degree in physical science from the United States Naval Academy and a master’s degree in engineering management from the Florida Institute of Technology in Melbourne, Florida. A retired US Navy captain, she is an experienced helicopter and fixed-wing pilot with more than 4,000 flight hours across 40 different aircraft.
“Anyone who knows me knows that space is my absolute favourite place to be,” Williams said.
“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. The International Space Station, the people, the engineering, and the science are truly awe-inspiring and have made the next steps of exploration to the Moon and Mars possible. I hope the foundation we set has made these bold steps a little easier. I am super excited for NASA and its partner agencies as we take these next steps, and I can’t wait to watch the agency make history,” she said.
