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.