• Boeing astronaut Chris Ferguson has stepped down from Boeing's 2021 crewed flight test
  • In a Twitter video, Ferguson stressed his dedication to the Starliner program and said it was a difficult decision
  • He will be replaced by a veteran NASA astronaut, giving the mission an all-NASA crew

The commander of the 2021 crewed Boeing flight test has stepped down from his position for "personal reasons." He will be replaced by another veteran astronaut.

NASA and Boeing announced on Wednesday that astronaut Chris Ferguson will no longer be the commander of next year's Boeing Crew Flight Test to the International Space Station (ISS). In their respective statements, both NASA and Boeing said Ferguson decided to step down from the mission for "personal reasons" but did not go into further details.

In a video Ferguson shared on Twitter, he stressed his dedication to the Starliner program, saying it was a difficult decision. He added that 2021 "is very important" for his family.

"I have made several commitments which I simply cannot risk missing," Ferguson said in the video. "I'm not going anywhere. I'm just not going into space next year."

Although he too did not specify why he stepped down, a Boeing spokeswoman told Associated Press that one of the "commitments" was his daughter's wedding.

"I'm taking on a new mission, one that keeps my feet planted here firmly on Earth and prioritizes my most important crew – my family," Ferguson said in the tweet.

In the Boeing and NASA statements, Ferguson reiterated his confidence in the Starliner vehicle, calling it the "safest new crewed spacecraft ever fielded." And even though he will not fly in the mission, he will remain active as the director of Mission Integration and Operations. This will be the first crewed mission of the Starliner spacecraft.

"In this role, Ferguson will be one of the last people the crew sees before leaving Earth and one of the first they see upon their return," the NASA statement said.

NASA veteran Barry "Butch" Wilmore will instead take Ferguson's place on the flight test, joining astronauts Nicole Mann and Mike Fincke.

Wilmore is an experienced astronaut who has spent a total of 178 days in space in two previous missions. As the sole back-up for all flight positions, Wilmore has been training with the crew since 2018.

"Butch will be able to step in seamlessly, and his previous experience on both space shuttle and space station missions make him a valuable addition to this flight," associate administrator for NASA's Human Exploration and Operations Mission Directorate, Kathy Lueders, said in the NASA news release.

Since Ferguson was supposed to be the only Boeing astronaut to fly as part of the mission and with his position filled by a NASA astronaut, the mission will now have an all-NASA crew.

Beoing and NASA are looking at a late 2020 or early 2021 repeat of their uncrewed test flight. The crewed mission is not expected to fly before June 2021.

This illustration, provided by Boeing in 2015, depicts the Starliner capsule in Earth orbit
This illustration, provided by Boeing in 2015, depicts the Starliner capsule in Earth orbit NASA/BOEING / HO