Veteran NASA astronaut Suni Williams retires after 27 years

Sunita L. "Suni" Williams ended a 27-year career at NASA when her retirement took effect Dec. 27, 2025, the agency announced, closing a chapter defined by long-duration station service, leadership roles and a dramatic final mission that tested the limits of commercial crew operations.

Williams, a 1998 astronaut select, flew three missions to the International Space Station. Her first trip came in 2006 aboard space shuttle Discovery as part of Expeditions 14/15. She returned to the station by Soyuz for Expeditions 32/33 in 2012, where she performed three spacewalks and served as station commander. Her third and final mission was the Boeing Starliner crewed test flight that launched June 5, 2024 and docked June 6, 2024.

The Starliner mission was planned as a brief test visit, with Williams and fellow astronaut Butch Wilmore expecting to spend roughly a week on orbit. A series of thruster anomalies during docking and subsequent vehicle concerns led NASA in September 2024 to direct Boeing to return the Starliner uncrewed for safety reasons. That decision left Williams, Wilmore and the rest of the station crew aboard far longer than planned. The four crewmembers returned to Earth aboard a SpaceX Dragon vehicle, departing the ISS on March 18, 2025 and splashing down off the coast of Florida that month after 286 days aboard the station.

Across her career, Williams logged 608 total days in space and set a record for female spacewalk time with 62 hours, 6 minutes. Her cumulative time and EVA total surpassed previous marks during the 2024-25 expedition and placed her among the most experienced U.S. astronauts in long-duration operations.

At NASA, Williams combined operational leadership with training and international duty. She served as deputy chief of the agency’s Astronaut Office, was director of Operations at Star City in Russia following her second mission, and helped establish a helicopter training platform to prepare crews for future lunar missions. Her early career included participation in NASA’s NEEMO undersea habitat in 2002. Before joining NASA, Williams was a U.S. Navy officer; she received a commission from the U.S. Naval Academy in May 1987, was designated a naval aviator in July 1989, logged more than 3,000 flight hours in over 30 aircraft and retired as a U.S. Navy captain.

Her service earned numerous honors, including two Distinguished Space Service Medals, the Legion of Merit, two Navy Commendation Medals and a Navy and Marine Corps Achievement Medal. NASA Administrator Jared Isaacman said Williams "has been a trailblazer in human spaceflight," noting her leadership aboard the space station and her role in paving the way for commercial low-Earth-orbit missions, Artemis Moon missions and future Mars work. Vanessa Wyche, director of NASA’s Johnson Space Center, called her "a pioneering leader" whose dedication will inspire future explorers.

Williams’s retirement punctuates a period of transition in U.S. human spaceflight as NASA balances agency-led programs with commercial partners. Her extended last mission highlighted both the promise and the risks of new crewed spacecraft, underscoring the agency’s reliance on multiple providers to maintain access to low-Earth orbit while advancing toward lunar and Martian objectives.