Suni Williams stepped down from her post on December 27 -- making her ill-fated mission her last journey to space.

Williams and fellow astronaut Barry "Butch" Wilmore set out on an eight-day mission in June 2024 to test fly Boeing's new Starliner capsule on its first crewed mission when they were unexpectedly marooned.

Despite the incident, Williams on Tuesday called her time with NASA "an incredible honor."

"Anyone who knows me knows that space is my absolute favorite place to be," she said in a statement.

Boeing's new Starliner developed propulsion issues while Williams and Wilmore were traveling to the International Space Station (ISS) and it was deemed unfit to fly back.

The technical problems prompted NASA to entrust the return of their astronauts to Elon Musk's SpaceX, snubbing Boeing.

The two veteran astronauts finally returned safely back to Earth with SpaceX in March 2025. Wilmore announced his retirement in August that same year.

NASA Administrator Jared Isaacman said in a statement on Tuesday that Williams had been a "trailblazer in human spaceflight," adding that she shaped the "future of exploration through her leadership aboard the space station" and paved the way for commercial missions to low Earth orbit.

During her career, Williams logged 608 days in space -- the second most cumulative time in space by a NASA astronaut, the agency said.

She also ranks sixth on the list of longest single spaceflights by an American due to the Starliner incident, NASA added.

Williams has completed nine spacewalks totaling 62 hours, the most spacewalk time by a woman and fourth-most on the all-time cumulative spacewalk duration list.