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

“Suni Williams was a pioneer 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 that advanced science and technology laid the groundwork for the Artemis missions to the Moon and progress 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 Time in Orbit and Spacewalk Milestones

During her missions, Williams spent a total of 608 days in space, ranking second among NASA astronauts for cumulative time away from Earth. He is also tied with NASA astronaut Butch Wilmore for the sixth longest solo space flight by an American astronaut. Each spent 286 days in orbit during NASA’s Boeing Starliner and SpaceX Crew-9 missions.

Williams completed nine spacewalks, totaling 62 hours and 6 minutes outside the space station. This total marks the highest time spent in space 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 in space.

“Throughout Suni’s impressive career, she has been a trailblazing leader,” said Vanessa Wyche, director of NASA’s Johnson Space Center in Houston. “From her indelible contributions and achievements on the space station to her groundbreaking role in a test flight during the Boeing Starliner mission, her exceptional mission commitment will inspire future generations of explorers.”

Early space shuttle missions

Williams made her first trip into space in December 2006, when she launched 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 the flight engineer for Expedition 14/15 and performed four spacewalks, which set a record at the time.

In 2012, Williams launched from the Baikonur Cosmodrome in Kazakhstan on a 127-day mission as part of Expedition 32/33. She served as the space station commander during Expedition 33. She made three spacewalks while in orbit to repair a leak in the station’s 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 a Boeing Starliner spacecraft for a NASA Crew Flight Test mission. Both later joined Expeditions 71/72, and Williams again took command of the space station during Expedition 72. She completed two more spacewalks and returned to Earth in March 2025 as part of NASA’s SpaceX Crew-9 mission.

“Suni is incredibly bright and an all-around great friend and colleague,” said Scott Tingle, chief of the Astronaut Office at NASA Johnson. “She inspired so many people, including me and the other astronauts in the corps. We will all miss her dearly and wish her the best.”

Williams also held several important leadership and training roles during her NASA career. In 2002, she participated in NEEMO (NASA Extreme Environments Mission Operations), where she spent nine days living and working in an underwater environment. After her first space flight, she served as deputy chief of NASA’s astronaut office. After her second mission, she became the Director of Operations at Star City, Russia. She recently helped establish a helicopter training platform to prepare astronauts for future moon landings.

A native of Needham, Mass., Williams earned a bachelor’s degree in physical science from the United States Naval Academy and a master’s degree in engineering management from the Florida Institute of Technology in Melbourne, Florida. She retired from the US Navy as a Captain and is an experienced helicopter and fixed wing pilot with over 4,000 flight hours in 40 different aircraft.

An outlook on NASA’s next chapter

“Anyone who knows me knows that space is my absolute favorite place,” Williams said. “It has been an incredible honor to serve in the astronaut office and I have had the opportunity to fly in space three times. I have had an amazing 27-year career at NASA, thanks in large part to all the amazing love and support I have received from my colleagues. The International Space Station, the people, the engineering and the science are truly awe-inspiring, and we have taken the next steps towards this small exploration of Mars and I hope that we have made possible a base for the moon and a bold foundation to the moon.” I am very excited for NASA and its partner agencies as we take these next steps, and I look forward to watching the agency make history.”

After 27 years of service, NASA astronaut Suni Williams retired from the agency effective December 27, 2025. Williams completed three missions aboard the International Space Station and set numerous records for human spaceflight during her career.

“Suni Williams was a pioneer 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 that advanced science and technology laid the groundwork for the Artemis missions to the Moon and progress 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 has logged 608 days in space – second on the list of cumulative time in space by a NASA astronaut. He is tied for sixth on the list of longest solo spaceflights by an American, shared with NASA astronaut Butch Wilmore, who both logged 286 days during NASA’s Boeing Starliner and SpaceX Crew-9 missions. Williams also completed nine spacewalks totaling 62 hours and 6 minutes, which ranks her as the woman with the most spacewalks and fourth on the all-time cumulative spacewalk list. She was also the first person to run a marathon in space.

“Throughout Suni’s impressive career, she has been a trailblazing leader,” said Vanessa Wyche, director of NASA’s Johnson Space Center in Houston. “From her indelible contributions and achievements on the space station to her groundbreaking role in a test flight during the Boeing Starliner mission, her exceptional mission commitment will inspire future generations of explorers.”

Williams first launched aboard Space Shuttle Discovery with STS-116 in December 2006 and returned aboard Space Shuttle Atlantis with crew STS-117. She served as flight engineer for Expedition 14/15 and completed a then-record four spacewalks during the mission.

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

Williams and Wilmore last launched aboard the Starliner spacecraft in June 2024 as part of NASA’s Boeing Crew Flight Test mission. She and Wilmore joined Expedition 71/72, and Williams reassumed command of the space station for Expedition 72. She completed two spacewalks and returned to Earth in March 2025 as part of the agency’s SpaceX Crew-9 mission.

“Suni is incredibly bright and an all-around great friend and colleague,” said Scott Tingle, chief of the Astronaut Office at NASA Johnson. “She inspired so many people, including me and the other astronauts in the corps. We will all miss her dearly and wish her the best.”

In addition to her experience in spaceflight, Williams held a number of roles during her career at NASA. In 2002, she served as a NEEMO (NASA Extreme Environments Mission Operations) crew member and spent nine days living and working in the underwater environment. After her first flight, she served as deputy chief of NASA’s astronaut office. She was later Director of Operations at Star City, Russia after her second mission to the space station. Most recently, she helped establish a helicopter training platform to prepare astronauts for future moon landings.

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

“Anyone who knows me knows that space is my absolute favorite place,” Williams said. “It has been an incredible honor to serve in the astronaut office and I have had the opportunity to fly in space three times. I have had an amazing 27-year career at NASA, thanks in large part to all the amazing love and support I have received from my colleagues. The International Space Station, the people, the engineering and the science are truly awe-inspiring and we have taken the next steps towards this small exploration of Mars and I hope that we have made possible a base on the moon and a bold foundation to the moon.” I am very excited for NASA and its partner agencies as we take these next steps, and I look forward to watching the agency make history.”