As a former NASA astronaut, he flew to space three times and was poised to make history as the first private citizen to fly to orbit on a commercially operated rocket. But Chris Ferguson, now a Boeing employee, announced on Wednesday he was pulling himself from the first crewed mission of the company’s Starliner spacecraft.

In an interview, Ferguson said that after 26 years in the Navy, where he served as a fighter pilot, then as a NASA astronaut and now as a Boeing executive, his career has put a strain on his family and forced him to be away repeatedly. Going to space next year for an extended stay on the International Space Station would force him to miss “a lot of key family events. … The year 2021 is shaping up so far as one that I should not be off the planet.”

NASA said he would be replaced by Barry “Butch” Wilmore, a veteran NASA astronaut who has flown to space twice and has been training on the Starliner spacecraft. He would join NASA astronauts Nicole Mann and Michael Fincke, who had previously been assigned to the mission.

Boeing hopes to launch a test flight of its Starliner spacecraft with the three astronauts no earlier than June of next year, after suffering a setbacks and delays that pushed it from its original flight date in 2017. A test mission in December of the spacecraft without any crews on board went awry when the onboard computer was 11 hours off, thinking the spacecraft was at a wrong point in the mission.

Crews on the ground were able to fix the software problem, but the mission was cut short. The spacecraft never docked with the space station as intended. Boeing said it would re-fly the mission in December or January, delaying the first flight with astronauts on board until mid-2021.

In the interview, Ferguson said he did not want to discuss the impact the delay had on his decision to step down. And he said it had nothing to do with the Starliner’s problems.

“I am passionately attached to this program. I have been dedicated from the very beginning. I absolutely love this team,” he said. “I enjoy being a part of it, and I have full confidence it’s going to be a robust and reliable vehicle for decades to come. This is no way a reflection of my belief in the vehicle.”

But he did say the delay of the flight into 2021 forced him to make a gut-wrenching decision: fly as planned, or miss some important events, including a family wedding, scheduled for next year.

“It was one of the more challenging life decisions I had to make,” he said in an interview. “It involved a little bit of staring in the mirror and saying, ‘Do I really need to do this?’ ”

Had he flown, Ferguson would have become the world’s first “corporate astronaut,” flying not under the NASA banner but as a Boeing employee who helped design and build the capsule from scratch. Boeing had hoped his presence on the mission would not only serve as a hands-on guide to the spacecraft, but also open up a new era of human spaceflight, where private citizens go to space alongside professionally trained astronauts.

NASA has ended a prohibition against allowing civilians to fly on American rockets to the space station. Now Boeing and SpaceX, the other company under contract to fly people to the space station, have been working to sign up wealthy individuals who would pay tens of millions of dollars for trips to orbit.

Ferguson was seen as a symbol of that progress. He served as the commander of the very last space shuttle mission in 2011 and hoped to restore human spaceflight to United States soil for NASA.

But after Boeing stumbled badly, Elon Musk’s SpaceX took the lead, and in May flew the first mission with astronauts to the space station since the shuttle retired.

“Having followed this vehicle along from the time it was just sketches on a drawing pad, to being able to sit in the real thing, but not being able to take it all the way, that’s going to smart a bit,” he said.

But he said he would be in mission control for the flight and that he would “live vicariously through this new crew.”

He held out the possibility that he might find a way to return to orbit on the Starliner: “I’m staying with Boeing so I’m not going anywhere,” he said. “I’m just not going to space next year.”