For Butch Wilmore and Suni Williams, the wait for this trip on the Boeing Starliner has been longer than they expected.
On May 1, a reporter pointed out that Mr. Wilmore and Ms. Williams, two veteran astronauts, trained longer for this mission than Neil Armstrong, Buzz Aldrin and Michael Collins had for the Apollo 11 moon landing.
“It almost feels unreal,” Ms. Williams replied.
Then the wait stretched out for almost another month after the first launch attempt on May 6 was called off because of a misbehaving valve in the rocket.
Mr. Wilmore and Ms. Williams initially remained at the Kennedy Space Center in Florida, hoping that the valve could be quickly fixed and that a second attempt could follow within a few days.
But engineers found a small helium leak in the Starliner, requiring arduous troubleshooting.
The two astronauts returned to their home base at the Johnson Space Center in Houston on May 10, but remained in quarantine to minimize contact with other people, and the chances of becoming ill.
“They’re in good spirits,” Steve Stich, program manager for NASA’s commercial crew program, said during a news conference on May 24.
Mr. Wilmore and Ms. Williams spent some of their additional time on the ground in a simulator for the Starliner spacecraft, practicing how to handle a failure of some of the spacecraft’s thrusters — a possible consequence if the helium leak worsened while they were in space.
“They’ve flown all those cases in terms of rendezvous and deorbit and entry, and they’re ready to go,” Mr. Stich said.
Ms. Williams was born in Ohio but grew up in Massachusetts. She was a test pilot in the U.S. Navy and has more than 3,000 hours flying 30 different aircraft. She was selected as a NASA astronaut in 1998. She has spent 322 days in space and for a while held the record for total time on spacewalks by a woman.
Mr. Wilmore, a native of Tennessee, was also a Navy test pilot, and he flew combat missions over Iraq and Bosnia in the 1990s. He was selected as an astronaut by NASA in 2000. During his two previous missions, he spent a total of 167 days in space.
Their last trips to orbit were years ago.
Ms. Williams had two long-duration stays on the International Space Station, the second ending in November 2012. Mr. Wilmore served as the pilot of a space shuttle mission in 2009, and then spent five and a half months on the space station from September 2014 to March 2015.
After a glitch-filled test flight in December 2019 with no crew aboard, delays shuffled the astronaut assignments. Indeed, none of the astronauts that NASA named in 2018 to fly on the test flight are on the upcoming test flight.
In 2020, Mr. Wilmore was named commander of the test flight. In 2022, Ms. Williams was shifted to the test flight, serving as the pilot. (She originally was assigned to serve as the commander of the second flight, the first operational one that would take four astronauts to the space station for six months.)