Boeing is gearing up for a highly-anticipated milestone as it prepares to launch its first Starliner flight with astronauts on board, marking a crucial test for the spacecraft that has faced lengthy delays. The launch is scheduled for 12:25 p.m. EDT on Saturday from Cape Canaveral, Florida.

The Starliner capsule will be carried to the International Space Station (ISS) by United Launch Alliance's Atlas V rocket, with two NASA astronauts on board. This launch attempt comes after a previous one in early May was postponed due to an issue with the rocket's valve, which has since been replaced.

However, this launch is not without its own challenges. NASA and Boeing discovered a small helium leak in the Starliner, which has prompted further assessments. After careful analysis, both entities have deemed the leak to be stable and not a safety concern.

Boeing's Starliner has faced numerous setbacks and delays, resulting in substantial financial costs. The company has reportedly incurred $1.5 billion in expenses related to Starliner setbacks, in addition to nearly $5 billion of NASA development funds. This has placed Starliner in a backup position for NASA's Commercial Crew program, with astronauts being reassigned to SpaceX's Dragon capsule.

The crew aboard the Starliner for this historic flight test will include Butch Wilmore as commander and Suni Williams as pilot. Both astronauts bring valuable space experience, with Wilmore having previously flown to space twice aboard the Space Shuttle and Soyuz. Williams, also a Navy pilot before joining NASA, has flown to space twice aboard the Space Shuttle and Soyuz as well.

The Starliner, which launches on ULA's Atlas V rocket, has had a storied history. This flight test represents the 100th launch for the Atlas V, which first debuted in 2002. The spacecraft itself is designed to accommodate up to four NASA astronauts and over 200 pounds of cargo and research. It is reusable and capable of undertaking up to 10 missions.

If the Starliner launch succeeds on Saturday, it will spend approximately 25 hours in space before docking with the ISS at 1:50 p.m. on Sunday. The astronauts will remain on the station for about a week, utilizing their time to test the Starliner's capabilities before returning to Earth.

This crew flight test marks a vital step towards receiving NASA certification for regular Starliner missions. Boeing is contracted to conduct six operational missions to the ISS, and the successful completion of this test will bring them closer to their goal.

As the industry eagerly awaits this pivotal launch, all eyes will be on Boeing and its Starliner spacecraft as they aim to prove their reliability and capability for future crewed space missions.