The Boeing Starliner spacecraft is set to return to Earth on Friday, months after docking with the space station and after NASA officials determined it could not fly back with a crew.

The spacecraft appeared to undock from the space station safely on Friday afternoon, ducking any problems that it had previously while docking when a thruster failed and helium leaked in its propulsion system. The spacecraft will return to New Mexico’s White Sands Missile Range six hours later.

The astronauts who rode to the space station on it, Butch Wilmore and Suni Williams, will stay behind until SpaceX brings them home in February.