Standing 30 stories tall, the partially reusable New Glenn launcher sat on Blue Origin's launchpad at the Cape Canaveral Space Force Station, ready for its 1:30 am ET (0630 GMT) liftoff after being loaded with methane and liquid oxygen propellants.

The mission, the culmination of a decade-long, multi-billion-dollar development journey, will include an attempt to land New Glenn's first stage booster on a sea-fairing barge in the Atlantic Ocean 10 minutes after liftoff, while the rocket's second stage continues toward orbit.

"The thing we're most nervous about is the booster landing," Bezos, who founded Blue Origin in 2000, told Reuters in a pre-launch interview. "Clearly on a first flight you could have an anomaly at any mission phase, so anything could happen."

Secured inside New Glenn's payload bay is the first prototype of Blue Origin's Blue Ring vehicle, a maneuverable spacecraft the company plans to sell to the Pentagon and commercial customers for national security and satellite servicing missions.

Getting the spacecraft to its intended orbit on an inaugural rocket launch would be a rare achievement for a space company.

"If we could do that, that would be a great success," Bezos said. "Landing the booster would be icing on the cake."

The development of New Glenn has spanned three Blue Origin CEOs and faced numerous delays as Elon Musk's SpaceX grew into an industry juggernaut with its reusable Falcon 9, the world's most active rocket.

Bezos in late 2023 moved to speed things up at Blue Origin, prioritizing the development of New Glenn and its BE-4 engines. He named Dave Limp, an Amazon veteran, as CEO, who employees say introduced a sense of urgency to compete with SpaceX.

New Glenn is more than twice as powerful as SpaceX's Falcon 9 rocket and has dozens of customer launch contracts collectively worth billions of dollars lined up.