Boeing launched its first Starliner flight with astronauts on Wednesday, beginning a crucial final flight test of the long-delayed spacecraft.

The launch took off at 10:52 a.m. ET from Cape Canaveral, Florida with two NASA astronauts aboard. Starliner is carried by an United Launch Alliance’s Atlas V rocket and bound for the International Space Station.

Wednesday’s liftoff comes after a series of attempts to launch the mission, which is known as the Boeing crew flight test. On Saturday, a launch attempt was called off in the final minutes of the countdown due to a problem with one of the computer’s that provides ground support to the rocket. In early May, another attempt was called off due to an issue detected with the rocket itself.