The first launch of the Boeing Starliner spacecraft with NASA astronauts

Boeing It aims to launch the first flight of the Starliner spacecraft with astronauts on board on Saturday, in a long-awaited final test of the spacecraft.

The launch is scheduled for 12:25 PM EST from Cape Canaveral, Florida. Two NASA astronauts will be aboard the Starliner capsule, which will be carried by United Launch Alliance's Atlas V rocket to the International Space Station.

NASA and Boeing canceled the launch attempt in early May because a problem was discovered with the rocket. ULA, a joint venture between Boeing and… Lockheed MartinReplace the problematic rocket valve.

After the May attempt was cancelled, NASA and Boeing found a “small” helium leak in the Starliner, prompting the agency and company to conduct another series of evaluations. After analysis, NASA and Boeing believe the source of the leak is in the spacecraft's helium propulsion system. But officials said last week that the leak was “stable” and “not related to aviation safety.”

The Starliner crew's debut has been delayed for years, as SpaceX's rival Dragon capsule has been carrying astronauts for NASA regularly since 2020 under the agency's Commercial Crew Program. So far, Boeing has incurred $1.5 billion in costs due to Starliner setbacks and nearly $5 billion in NASA development money.

The spacecraft was once seen as a competitor to SpaceX's Dragon. However, various setbacks and delays have steadily placed the Starliner in a backup position for NASA, with the agency taking the rare step of reassigning astronauts from Boeing's first crewed flights in 2021. Boeing is contracted to fly six operational Starliner missions to the space station International. Saturday's crew flight test marks the last major step before NASA receives certification to begin regular missions.

Butch Wilmore and Sonny Williams fly the Starliner, with the former serving as the spacecraft's commander and the latter as its pilot.

Wilmore joined NASA in 2020 and has flown into space twice previously aboard the Space Shuttle and Russia's Soyuz spacecraft. Before NASA, Wilmore was a pilot in the US Navy.

Williams was selected by NASA in 1998 and has flown into space twice before, on the space shuttle and then on the Soyuz spacecraft. Williams was also a Navy aviator like Wilmore before joining the space agency.

Starliner was launched aboard ULA's Atlas V. The rocket debuted in 2002, and the Starliner crew flight test marks its 100th launch.

The capsule itself is designed to carry up to four NASA astronauts per flight and more than 200 pounds of research and cargo. The spacecraft lands using a parachute and airbag system. The Starliner is reusable, with each pod designed to fly up to 10 missions.

The Boeing crew flight test aims to certify that the Starliner system is capable of carrying NASA astronauts to and from the International Space Station.

If the Starliner launches on Saturday, it will fly in space for about 25 hours before the planned docking with the International Space Station at 1:50pm on Sunday. The astronauts will then spend about a week on the International Space Station, focusing on testing the Starliner, before returning to Earth.