NASA is delaying its next astronaut launch to buy more time at the International Space Station for Boeing’s troubled new crew capsule.

The space agency said Tuesday it’s bumping SpaceX’s four-person flight from this month to next. It’s now targeted for Sept. 24 at the earliest. Officials said that will give them more time to analyze thruster and leak problems that hit Boeing’s Starliner capsule after its June liftoff, its first with a crew on board.

Tuesday marked the two-month point at the space station for Starliner’s test pilots, Butch Wilmore and Suni Williams, who should have been back by mid-June. NASA is weighing all its options for returning the two veteran astronauts, including a ride home in a SpaceX capsule.