It is an important step for Boeing. A successful unmanned test flight to the ISS is a prerequisite for being allowed to transport astronauts for NASA. An earlier attempt at the end of 2019 failed. A computer error with the system clock sent the capsule into a wrong orbit, preventing it from reaching the ISS.
The capsule then returned safely to Earth, but later two more software bugs were discovered that could have been catastrophic. Boeing also turned out not to have tested all systems under the right conditions.
After research by Boeing and NASA, Boeing made dozens of corrections. But due to further software problems and a problem with the shut-off valves of the propellant rockets, a new test flight was repeatedly postponed. On Thursday, the Starliner finally took off from the Florida launch site, atop an Atlas V rocket.