Boeing Starliner's first crewed mission to ISS delayed again

The latest: NASA test pilots Butch Wilmore and Suni Williams were already aboard the Starliner when the mission was called off, roughly two hours before launch time, NASA wrote on X Monday night.

• The mission was derailed due to an issue with a valve on the Atlas V rocket meant to power the Starliner into space, NASA added.
• NASA said in a blog post Tuesday that it is planning a next launch attempt for no sooner than May 10.

Catch up quick: The Starliner had been scheduled to launch at 10:34pm ET on Monday from Cape Canaveral Space Force Station in Florida, according to NASA.

• Starliner was expected to dock with the ISS around 12:40am ET on May 8.

State of play: The crewed test was scheduled after years of delays from technical problems with Starliner that required Boeing to rework aspects of the craft and conduct additional uncrewed test flights.

• Among the malfunctions: stuck propulsion system valves, software glitches and the use of hundreds of feet of protective tape that was flammable.

• The program setbacks have added up to at least $1.5 billion in overrun costs for Boeing. NASA originally awarded the company a $4.2 billion fixed-priced contract in 2014 to develop Starliner.

The big picture: A successful test is vital for Starliner to be certified as an operational crew system by NASA.

• If it's certified, Boeing may begin routine operational flights to the ISS through NASA's Commercial Crew Program as early as 2025.

Go deeper: Congestion in Earth's orbit is getting even worse

Editor's note: This story was updated to reflect the scheduled launch was delayed.