Boeing's troubled Starliner, leaving its crew behind, set for unpiloted return to Earth

Boeing's troubled Starliner spacecraft — not trusted by NASA to safely bring its crew home from the International Space Station — was rigged for undocking Friday and an unpiloted return to Earth to close out a disappointing test flight marred by helium leaks and thruster problems.

Leaving Starliner commander Barry "Butch" Wilmore and pilot Sunita Williams behind, the Boeing spacecraft was expected to undock from the station's forward port at 6:04 p.m. EDT.

Looping up over the station to a point well above and behind the lab complex, the Starliner's braking rockets were expected to fire at 11:17 p.m. to drop the ship out of orbit, setting up a fiery re-entry plunge to landing at White Sands, New Mexico, just after midnight Eastern Time.