HMM: Increasingly, the ULA-Blue Origin marriage is an unhappy one.

Privately, multiple sources say, the relationship between Blue Origin and United Launch Alliance is not good. “There is great concern about this engine development,” one person in the industry said. “It’s much more than Tory Bruno is showing publicly. There is great concern that Blue is not putting enough attention and priority on the engine.”

For years, United Launch Alliance chief executive Tory Bruno had been saying the new Vulcan rocket, powered by two BE-4 engines, would launch in 2021. However, he recently told Aviation Week the first launch would slip into 2022. Bruno said this was due primarily to the mission’s customer, Astrobotic, whose Moon lander was not ready. Technically, Bruno said, Vulcan still had a chance to be ready for a 2021 launch.

This seems highly unlikely because it is already July, and United Launch Alliance (ULA) still does not have a pair of flight engines. After receiving the flight engines from Blue Origin, ULA needs to attach them to the Vulcan rocket, roll it to the launch pad, and conduct a lengthy series of tests before a hot-fire ignition. After this hot-fire test, the rocket will be rolled back to the hangar and prepared for an actual launch attempt. As of January, Bruno was saying this hot fire test with the flight engines would take place this summer. That will no longer happen.

In response to a question from Ars, ULA declined to offer an updated timeline for when it expects to take delivery of flight-ready BE-4 engines from Blue Origin.

ULA chose Blue Origin’s BE-4 engine back in 2014 to power its Vulcan heavy lift rockets — and seven years later no BE-4 has reached orbit.