Jeff Bezos' space company, Blue Origin, is reportedly falling out of favor with one of its largest customers.
The United Launch Alliance (ULA) is planning to use two of Blue Origin's BE-4 rocket engines to build its Vulcan rocket, a two-stage, heavy-lift launch vehicle that's currently under development.
It's an agreement that dates back almost seven years. But the engine is now years behind schedule, as Ars Technica's Eric Berger reports, to the dismay of ULA's leadership.
"There is great concern about this engine development," an industry insider told Berger. "It's much more than [ULA CEO] Tory Bruno is showing publicly. There is great concern that Blue is not putting enough attention and priority on the engine."
Bruno is still publicly optimistic, claiming back in December that Vulcan still has a chance to launch some time this year — but a 2022 launch is far more likely, Berger argues. A hot fire test of the rocket, including flight engines, was scheduled for this summer but has yet to take place.
The CEO, however, has been unusually patient with Blue Origin and hasn't publicly griped about the delays.
"It does no good to throw Blue Origin under the bus," an unnamed source told Berger.
ULA's current tried-and-true Atlas V rocket uses Russian rocket engines — and as US-Russia relations have soured over the years, the rocket became increasingly unpopular among lawmakers.
So the SpaceX competitor had to go out looking for an alternative. In 2014, ULA chose Blue Origin's BE-4 over rocket developer Aerojet Rocketdyne's AR1.
Aerojet may not be entirely out of the race, Berger reports. In fact, ULA co-owner Lockheed is looking to acquire the rocket maker.
But reversing its decision to go with the BE-4 could prove extremely difficult. Even the AR-1 won't be fired up until late last year, according to CNBC. The two engines also use different sources of fuel, requiring extensive modifications.
So for now, ULA is stuck while its waiting for Blue Origin to finalize its BE-4 engine. Even Bezos's flight to the edge of space later this month won't be much of a distraction.
READ MORE: Increasingly, the ULA-Blue Origin marriage is an unhappy one [Ars Technica]