Suni Williams, one of the NASA astronauts whose trip to the International Space Station was extended from days to months, has retired from the agency.
NASA announced her retirement, saying that it was effective on Dec. 27, 2025.
“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 in a news release. “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.”
Williams is originally from Needham, Massachusetts, and has a bachelor’s degree in physical science from the U.S. Naval Academy.
She earned a master’s degree in engineering management from Florida Institute of Technology in Melbourne, Florida.
The retired Navy captain is also a helicopter pilot and fixed-wing pilot, logging more than 4,000 flight hours in 40 different aircraft, NASA said.
But space is her place.
“Anyone who knows me knows that space is my absolute favorite place to be,” Williams said in the announcement. “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.”
Williams first went into space on the shuttle Discovery in 2006 and returned on the shuttle Atlantis. She then went back in 2012 as part of Expedition 32/33 and became the space station commander for Expedition 33.
Williams had 608 days in space, the second-longest cumulative time in space by a NASA astronaut.
She also performed the sixth-longest single spaceflight by an American. Williams and is tied with Butch Wilmore. Both were on the Boeing Starliner as part of a test mission and then returned to Earth as part of SpaceX Crew-9 in March 2025, after there were issues with the Starliner, which kept the pair on the ISS for 286 days.
Williams also completed nine spacewalks for 62 hours and six minutes, the longest amount of time for a female astronaut and the fourth most cumulative hours.
She has done something that no one else has: run a marathon in space, NASA said.
Williams didn’t just contribute to NASA with her trips into space. She was part of the NEEMO crew, or NASA Extreme Environments Mission Operations, living for nine days in an underwater habitat.
She was the director of Operations in Star City, Russia, and established a helicopter training platform to help future astronauts for moon missions, NASA said.