NASA astronaut Suni Williams retires after 608 days in space and nine spacewalks

“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.”

Record-Setting Time in Orbit and Spacewalk Milestones

Across her missions, Williams spent a total of 608 days in space, placing her second among NASA astronauts for cumulative time off Earth. She also ranks sixth for the longest single spaceflight by an American astronaut, tied with NASA astronaut Butch Wilmore. Each spent 286 days in orbit during NASA’s Boeing Starliner and SpaceX Crew-9 missions.

Williams completed nine spacewalks, adding up to 62 hours and 6 minutes outside the space station. That total stands as the highest amount of spacewalk time achieved by a woman and the fourth-highest cumulative total of all time. She also made history by becoming 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.”

Early Space Shuttle Missions

Williams made her first trip to space in December 2006, launching aboard space shuttle Discovery on mission STS-116. She returned to Earth with the STS-117 crew aboard space shuttle Atlantis. During this mission, she served as a flight engineer for Expeditions 14/15 and carried out four spacewalks, which set a record at the time.

In 2012, Williams launched from the Baikonur Cosmodrome in Kazakhstan for a 127-day mission as part of Expedition 32/33. During Expedition 33, she served as commander of the space station. While in orbit, she performed three spacewalks to repair a leak in a station radiator and replace a component that transfers power from the station’s solar arrays to its systems.

Starliner Test Flight and Final Mission

Williams’ most recent mission began in June 2024, when she and Wilmore launched aboard Boeing’s Starliner spacecraft for NASA’s Crew Flight Test mission. The two later joined Expeditions 71/72, and Williams once again took command of the space station during Expedition 72. She completed two additional spacewalks and returned to Earth in March 2025 as part of NASA’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.”

Williams also held several important leadership and training roles throughout her NASA career. In 2002, she took part in NEEMO (NASA Extreme Environments Mission Operations), spending nine days living and working in an underwater habitat. After her first spaceflight, she served as deputy chief of NASA’s Astronaut Office. Following her second mission, she became director of Operations in Star City, Russia. More recently, she helped establish a helicopter training platform to prepare astronauts for future Moon landings.

Originally from 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 Florida Institute of Technology in Melbourne, Florida. She retired from the U.S. Navy as a captain and is an experienced helicopter and fixed-wing pilot, with more than 4,000 flight hours across 40 different aircraft.

Looking Ahead to NASA’s Next Chapter

“Anyone who knows me knows that space is my absolute favorite place to be,” said Williams. “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.”

After 27 years of service, NASA astronaut Suni Williams retired from the agency, effective Dec. 27, 2025. Williams completed three missions aboard the International Space Station, setting numerous human spaceflight records throughout her career.

“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.”

Williams logged 608 days in space — second on the list ofcumulative time in spaceby 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, totaling 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 also 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.

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.”

Beyond her spaceflight experience, Williams held numerous roles throughout her NASA career. In 2002, she served as a NEEMO (NASA Extreme Environments Mission Operations) crew member, spending nine days living and working in an underwater habitat. After her first flight, she served as deputy chief of NASA’s Astronaut Office. She later was the director of Operations in Star City, Russia, following her second mission to the space station. Most recently, she helped establish ahelicopter training platformto prepare astronauts for future Moon landings.

The Needham, Massachusetts, native holds a bachelor’s degree in physical science from the United States Naval Academy and a master’s degree in engineering management from Florida Institute of Technology in Melbourne, Florida. A retired U.S. Navy captain, Williams is an accomplished helicopter and fixed-wing pilot, having logged more than 4,000 flight hours in 40 different aircraft.

“Anyone who knows me knows that space is my absolute favorite place to be,” said Williams. “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.”