Williams concluded a remarkable 27-year career marked by record-setting missions and leadership roles aboard the International Space Station (ISS). She flew on three space missions, contributing significantly to human spaceflight, space station operations, and future deep-space exploration.

“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 extraordinary achievements will continue to inspire generations to dream big and push the boundaries of what’s possible.”

Over her career, Williams logged 608 days in space, ranking second among NASA astronauts for cumulative time spent in orbit. She also ranks sixth for the longest single spaceflight by an American, tied with astronaut Butch Wilmore, with both spending 286 days in space during NASA’s Boeing Starliner and SpaceX Crew-9 missions.

Williams completed nine spacewalks, totaling 62 hours and six minutes, making her the woman with the most spacewalk time and placing her fourth on the all-time cumulative spacewalk duration list. She is also known as the first person to run a marathon in space.

“Over the course of Suni’s impressive career, she has been a pioneering leader,” said Vanessa Wyche, director of NASA’s Johnson Space Center in Houston. “From her contributions to the space station to her groundbreaking role during the Boeing Starliner test flight, her dedication will inspire future generations of explorers.”

Williams made her first spaceflight in December 2006, launching aboard space shuttle Discovery (STS-116) and returning on Atlantis (STS-117). She served as a flight engineer for Expeditions 14 and 15, during which she completed a then-record four spacewalks.

In 2012, she launched from the Baikonur Cosmodrome in Kazakhstan for a 127-day mission as part of Expeditions 32 and 33, later commanding the ISS during Expedition 33. During the mission, she conducted three spacewalks to repair a radiator leak and replace a critical power system component.

Her most recent mission came in June 2024, when Williams and Wilmore launched aboard Boeing’s Starliner for NASA’s Crew Flight Test. The duo joined Expeditions 71 and 72, with Williams once again serving as space station commander. She completed two additional spacewalks before returning to Earth in March 2025 aboard SpaceX’s Crew-9.

“Suni is incredibly sharp and an all-around great friend and colleague,” said Scott Tingle, chief of NASA’s Astronaut Office. “She’s inspired so many people, including those of us in the astronaut corps.”

Beyond spaceflight, Williams held several key leadership roles at NASA. She participated in NASA’s NEEMO underwater mission, served as deputy chief of the Astronaut Office, led operations in Star City, Russia, and most recently helped establish a helicopter training platform to prepare astronauts for future Moon landings.

A native of Needham, Massachusetts, Williams holds a bachelor’s degree from the US Naval Academy and a master’s degree from the Florida Institute of Technology. A retired US Navy captain, she has logged over 4,000 flight hours in more than 40 aircraft.

“Space has always been my favorite place to be,” Williams said. “It’s been an incredible honor to fly in space three times and serve alongside such amazing people. I’m excited to watch NASA and its partners continue making history as we return to the Moon and move toward Mars.”