Boeing and NASA said Wednesday the first crewed flight of the CST-100 Starliner spacecraft to the International Space Station will move back to no earlier than July 21.

“There are really no issues with the product,” Boeing Vice President Mark Nappi said. Rather, the delay is caused by issues such as scheduling at the busy Cape Canaveral Space Force Station in Florida and officially certifying the parachute system.

“At this time, there’s really no issues or concerns with the parachute system,” said Steve Stich, manager of NASA’s Commercial Crew Program. “The parachutes are installed in the vehicle, they’re in good shape, but it’s just a matter of going through all that data and looking at the data to make sure we’re ready to go fly safely.”

The demonstration flight will carry two NASA astronaut test pilots – Butch Wilmore and Suni Williams – and will aim to prove “end-to-end capabilities” of the spacecraft. That will allow it to make regular space station crew rotation flights along with SpaceX’s Dragon capsule.

Starliner will launch atop a United Launch Alliance Atlas V rocket built at the company’s rocket factory in Decatur, Ala. The spacecraft itself was designed in Huntsville by Boeing’s design laboratory.

The Starliner will land after the mission at the White Sands Missile Range’s Space Harbor. It has already landed there in an earlier uncrewed trip to the space station. Boeing hoped to be able to launch the crewed flight in April.