SpaceX’s Crew Dragon astronaut capsule will be ready for its first manned test flight into orbit in the first quarter of next year, provided that “everything goes according to plan” in upcoming tests, NASA chief Jim Bridenstine said on Thursday.

On a visit to the SpaceX headquarters, Bridenstine praised Elon Musk’s company for its “fail fast, then fix” approach to spacecraft design after a personal tour and briefing at the sprawling manufacturing plant – a display of unity amid a rare public spat between the two key space figures.

The National Aeronautics and Space Administration is paying commercial launch contractors SpaceX and Boeing Co $6.8 billion to build rocket-and-capsule systems to return astronauts to the International Space Station from U.S. soil for the first time since America’s space shuttle program ended in 2011.

Bridenstine’s visit to SpaceX headquarters in the Los Angeles suburb of Hawthorne comes as SpaceX works to overcome key technical challenges on the Crew Dragon. SpaceX has so far never flown humans into orbit, only cargo.

Musk and Bridenstine said they were working together through concerns over re-entry parachutes and other technical challenges, some of which were first publicly detailed by Reuters.

“It’s a pretty arduous engineering job to get the parachutes right,” Musk said, declaring that Crew Dragon’s parachutes will have “twice the safety factor” than those used in the Apollo era.“Testing will be complete and hardware at the Cape by the end of December,” he added.