Washington DC [US], January 21 (ANI): NASA astronaut Suni Williams has retired after 27 years of service, effective December 27, 2025.

With a remarkable career spanning three missions aboard the International Space Station, Williams has set numerous human spaceflight records, including logging 608 days in space, the second-most cumulative time by a NASA astronaut.

'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,' said NASA Administrator Jared Isaacman. '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 logged 608 days in space -- second on the list of cumulative time in space by a NASA astronaut. She ranks sixth on the list of longest single spaceflight by an American, tied with NASA astronaut Butch Wilmore, both logging 286 days during NASA's Boeing Starliner and SpaceX Crew-9 missions.

Williams also completed nine spacewalks, totalling 62 hours and 6 minutes, ranking as the most spacewalk time by a woman and fourth-most on the all-time cumulative spacewalk duration list. She was the first person to run a marathon 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 launched for the first time aboard space shuttle Discovery with STS-116 in December 2006 and returned aboard space shuttle Atlantis with the STS-117 crew. She served as a flight engineer for Expeditions 14/15 and completed a then-record-breaking four spacewalks during the mission.

In 2012, Williams launched from the Baikonur Cosmodrome in Kazakhstan for a 127-day mission as a member of Expedition 32/33. She also served as space station commander for Expedition 33. Williams performed three spacewalks during the mission to repair a leak on a station radiator and replace a component that gets power from the station's solar arrays to its systems, the statement said.

Most recently, Williams and Wilmore launched aboard the Starliner spacecraft in June 2024 as part of NASA's Boeing Crew Flight Test mission. She and Wilmore went on to join Expedition 71/72, and Williams again took command of the space station for Expedition 72. She completed two spacewalks on the mission and returned to Earth in March 2025, as part of the agency's 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.'