The cancellation of the inaugural manned space mission comes as Boeing is under fire over the safety record of its aviation division.
Boeing canceled the crewed maiden flight of the CST-100 Starliner space capsule after engineers detected a problem with a valve on the rocket.
The decision to cancel the launch on Monday came two hours before the scheduled liftoff and about an hour after two NASA astronauts boarded the spacecraft.
The postponement, attributed to a problem with a valve on the Atlas V rocket, was announced during a live NASA webcast.
“Give up tonight's launch attempt,” NASA chief Bill Nelson said in a post on X.
“As I said before, @NASA's first priority is safety. We will leave when we are ready.”
It was not immediately clear how long it would take to fix the issue, but the next available release windows for launch are Tuesday, Thursday and Friday nights.
Give up tonight's launch attempt #Starliner. As I said before, @POTThe first priority is safety. We leave when we are ready.
-Bill Nelson (@SenBillNelson) May 7, 2024
The Starliner was to transport NASA astronauts Butch Wilmore and Suni Williams to the International Space Station (ISS), where they would have spent a week before returning to Earth.
The Starliner's maiden voyage to the ISS has been closely watched as a sign of Boeing's ability to rival Elon Musk's SpaceX for NASA contracts.
In 2014, NASA awarded multimillion-dollar contracts to Boeing and SpaceX to develop space capsules for the space agency to transport astronauts and cargo to space.
The contracts marked the beginning of NASA's shift toward public-private partnerships following the end of its space shuttle program.
SpaceX's Dragon successfully transported astronauts to the ISS in 2020, marking the first time NASA astronauts launched from US soil on a commercially built spacecraft.
Starliner made its first unmanned mission to the ISS in 2022, after a failed attempt three years earlier.
The cancellation of Monday's launch comes at a difficult time for Boeing, as the company grapples with several investigations into alleged safety lapses in its aviation division.
