An unpiloted test flight of Boeing’s Starliner crew capsule to the International Space Station will be delayed from its previous target launch date of April 2 until at least May, after the arrivals of Russian Soyuz and SpaceX Crew Dragon ships bringing fresh crew members to the orbiting complex, NASA officials said Monday.

A commercial Antares rocket rolled out of a hangar on a one-mile trip to its launch pad on Virginia’s Eastern Shore on Thursday, ready for final countdown preparations ahead of liftoff Saturday morning on a cargo delivery flight to the International Space Station.

Three space station crew members packed up for a fiery return to Earth Thursday, wrapping up a nearly 200-day mission that was extended one month at the last minute because of a Russian rocket failure in April that threw a wrench into the lab’s crew rotation schedule.