Boeing's new Starliner astronaut capsule was poised for launch on Monday night on a much-delayed first crewed test flight to orbit, as the company scrambles to compete with Elon Musk's SpaceX for a greater share of lucrative NASA business.

NASA has scrubbed the launch of Boeing’s Starliner, which was set to send two astronauts to the International Space Station. The cited reason for the postponement was a complication with an oxygen relief valve on the solid rocket booster.

Boeing scrubbed its Monday launch attempt of its new Starliner spacecraft, crewed by veteran NASA astronauts Suni Williams and Butch Wilmore.

The long-awaited first crewed test flight of Boeing's new Starliner space capsule was called off for at least 24 hours over a technical issue that launch teams were unable to resolve in time for the planned Monday night lift-off.

Two astronauts will put the Boeing Starliner through its paces to verify it's ready to begin launching operational crew ferry flights to the space station.