Boeing Starliner's first astronaut-crewed flight launch called off due to stuck valve

Boeing's first astronaut-crewed flight into space has been called off due to a stuck valve on the spacecraft’s rocket Monday, the United Launch Alliance announced.

The Starliner Crew Flight Test, developed in collaboration with NASA's Commercial Crew Program, was set to launch from Space Launch Complex-41 atop an Atlas V rocket at Cape Canaveral Space Force Station in Florida at 10:34 p.m. ET before it was called off.

"ULA Launch Director Tom Heter III has made the decision to the launch team that launch operations will not continue tonight," the United Launch Alliance said in an update on X (formally Twitter) Monday evening.

The Starliner will now launch no later than May 17, the team announced Tuesday.

The Starliner is designed to carry a seven-person crew, but aboard the "test drive" launch will be NASA astronauts Barry Wilmore, 61, a former U.S. Navy captain who will be commanding the flight, and Sunita Williams, 58, a former Navy service member who will be piloting the flight.

Before the delay, the capsule was scheduled to reach the ISS in 26 hours. Wilmore and Williams were set to stay at the station for nearly a week before returning to Earth aboard the Starliner once more.

Monday would have marked the first crewed flight for Boeing's Starliner, which has faced several setbacks and delays along its rival journey with Space X's Crew Dragon, also a part of NASA's Commercial Crew Program.

During the Starliner's first test launch in 2019, the unpiloted capsule failed to make it to the space station because a software error stopped the capsule's flight computer from loading the correct launch time, according to the aerospace company at the time.

The second official launch, also unpiloted, came in May 2022 and was a success, Boeing said at the time, with the Starliner reaching and docking at the space station and safely returning and landing back on Earth.

Despite the success, crews found issues with the capsule's parachute system and that adhesive tape used to cover wiring on the spacecraft could be flammable, according to Boeing.

These issues ultimately delayed Boeing's planned, crewed launch another year, from 2023 to 2024.

During a press conference last week, Mark Nappi, Boeing vice president and program manager of the Commercial Crew Program maintained, "We are to a state now where we are ready to perform the test flight."

"I've never felt readier on any mission that I've ever participated in," he said.