After years of delays and stumbles, Boeing is finally poised to launch astronauts to the International Space Station for NASA.

Its the first flight of Boeings Starliner capsule with a crew on board, a pair of NASA pilots who will check out the spacecraft during the test drive and a weeklong stay at the space station.

NASA turned to U.S. companies for astronaut rides after the space shuttles were retired. Elon Musks SpaceX has made nine taxi trips for NASA since 2020, while Boeing has managed only a pair of unoccupied test flights.

Boeing program manager Mark Nappi wishes Starliner was further along. Theres no doubt about that, but were here now.

The companys long-awaited astronaut demo is slated for liftoff Monday night.

Provided this tryout goes well, NASA will alternate between Boeing and SpaceX to get astronauts to and from the space station.

A look at the newest ride and its shakedown cruise:

THE CAPSULE

White with black and blue trim, Boeings Starliner capsule is about 10 feet (3 meters) tall and 15 feet (4.5 meters) in diameter. It can fit up to seven people, though NASA crews typically will number four. The company settled on the name Starliner nearly a decade ago, a twist on the name of Boeings early Stratoliner and the current Dreamliner.

No one was aboard Boeings two previous Starliner test flights. The first, in 2019, was hit with software trouble so severe that its empty capsule couldnt reach the station until thesecond tryin 2022. Then last summer, weak parachutes and flammable tape cropped up that needed to be fixed or removed.

THE CREW

Veteran NASA astronauts Butch Wilmore and Suni Williams are retired Navy captains who spent months aboard the space station years ago. They joined the test flight after the original crew bowed out as the delays piled up. Wilmore, 61, is a former combat pilot from Mount Juliet, Tennessee, and Williams, 58, is a helicopter pilot from Needham, Massachusetts. The duo have been involved in the capsules development and insist Starliner is ready for prime time, otherwise they would not strap in for the launch.

Were not putting our heads in the sand, Williams told The Associated Press. Sure, Boeing has had its problems. But we are the QA (quality assurance). Our eyes are on the spacecraft.

THE TEST FLIGHT

Starliner will blast off on United Launch Alliances Atlas V rocket from Cape Canaveral Space Force Station. It will be the first time astronauts ride an Atlas since NASAs Project Mercury, starting with John Glenn when he became the first American to orbit the Earth in 1962. Sixty-two years later, this will be the 100th launch of the Atlas V, which is used to hoist satellites as well as spacecraft.

Were super careful with every mission. Were super, duper, duper careful with human missions, said Tory Bruno, CEO of ULA, a joint venture of Boeing and Lockheed Martin.

Starliner should reach the space station in roughly 26 hours. The seven station residents will have their eyes peeled on the approaching capsule. The arrival of a new vehicle is a really big deal. You leave nothing to chance, NASA astronaut Michael Barratt told the AP from orbit. Starliner will remain docked for eight days, undergoing checkouts before landing in New Mexico or elsewhere in the American West.

STARLINER VS. DRAGON

Both companies capsules are designed to be autonomous and reusable. This Starliner is the same one that made the first test flight in 2019. Unlike the SpaceX Dragons, Starliner has traditional hand controls and switches alongside touchscreens and, according to the astronauts, is more like NASAs Orion capsules for moon missions. Wilmore and Williams briefly will take manual control to wring out the systems on their way to the space station.

NASA gave Boeing, a longtime space contractor, more than $4 billion to develop the capsule, while SpaceX got $2.6 billion. SpaceX already was in the station delivery business and merely refashioned its cargo capsule for crew. While SpaceX uses the boss Teslas to get astronauts to the launch pad, Boeing will use a more traditional astrovan equipped with a video screen that Wilmore said will be playing Top Gun: Maverick.

One big difference at flights end: Starliner lands on the ground with cushioning airbags, while Dragon splashes into the sea.

THE FUTURE

Boeing is committed to six Starliner trips for NASA after this one, which will take the company to the stations planned end in 2030. Boeings Nappi is reluctant to discuss other potential customers until this inaugural crew flight is over. But the company has said a fifth seat will be available to private clients. SpaceX periodically sells seats to tycoons and even countries eager to get their citizens to the station for a couple weeks.

Coming soon: Sierra Spaces mini shuttle, Dream Chaser, which will deliver cargo to the station later this year or next, before accepting passengers.

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