Nearly 29 months have passed since the company's first attempt to demonstrate that Starliner could safely launch into orbit, fly up to the International Space Station and dock, and then return to Earth in a New Mexico desert beneath three parachutes.

During that December 2019 test flight, of course, there were myriad software problems, and Starliner ended up lacking the fuel to rendezvous with the space station.

As part of its fixed-price contract with NASA—the space agency is paying about $5.1 billion to Boeing to develop a crew transport system to the space station—the company agreed to redo the demonstration flight.

Today's launch is scheduled to take place at 6:54 pm ET (22:54 UTC) on top of an Atlas V rocket from Cape Canaveral Space Force Station.

The space agency, meanwhile, would very much like a second means of reaching the space station.

It is confident in the capability of SpaceX's Crew Dragon vehicle—for which NASA paid $3.1 billion and has been safely flying astronauts since mid-2020—but with uncertainty in Russia the space agency can no longer count on access to the Soyuz vehicle.

One of NASA's astronauts who will fly on an early Starliner mission, Butch Wilmore, said during a news conference Wednesday that Boeing and the space agency were confident ahead of Thursday's launch attempt.

The mission ops folks that will control the spacecraft in space are ready.

If all goes well with the launch, the uncrewed Starliner spacecraft will dock with the space station on Friday, at 7:10 pm ET (23:10 UTC).