Jeff Bezos’ Blue Origin is frustrating one of its closest partners with rocket engine delays, according to a report

• The United Launch Alliance is frustrated with Blue Origin for delays to rocket engines, sources told Ars Technica.
• Jeff Bezos' Blue Origin is building two rocket engines for ULA's Vulcan rocket, but they're still not finished.
• "There is great concern that Blue is not putting enough attention and priority on the engine," one industry source said.
• See more stories on Insider's business page.

Blue Origin's relationship with one of its closest partners, the United Launch Alliance (ULA), has soured over delays to rocket engines, according to a new Ars Technica report.

Blue Origin, Jeff Bezos' aerospace company, is building two engines for the ULA's Vulcan rocket. The ULA wanted to launch the rocket into space this year, but the engines have been delayed, Ars reported. The Vulcan rocket is a two-stage launch vehicle that is set to send satellites into orbit for the US Space Force.

"There is great concern about this engine development," one industry source told Ars. "There is great concern that Blue is not putting enough attention and priority on the engine."

ULA CEO Tory Bruno isn't showing the full extent of his concern to the public, the source added.

"He's protecting Blue Origin," a second industry source told Ars, commenting on Bruno's lack of public criticism of the engine delay. "It does no good to throw Blue Origin under the bus."

Bruno had previously said he expected the rocket to launch in 2021. But he told Aviation Week in June that the first launch had been nudged back to 2022.

Blue Origin and the ULA announced their partnership to fund the development of the new BE-4 rocket engines in 2014.

The ULA may not be happy with how its collaboration with Blue Origin worked out, "but for now they have no recourse but to make the marriage with Blue Origin work," a third industry source told Ars.

Space Force officials are also annoyed about the delay because they want to start flying the rocket, the sources told Ars. This additional tension has put even more pressure on Blue Origin engineers, they added.

Insider asked the ULA and Blue Origin for comment, but did not immediately receive a response.

The ULA declined to comment to Ars on when Blue Origin's rocket engines are expected to be finished. It also declined to comment to Ars on any fallout with Bezos' company.

Industry sources told Ars the ULA chose Blue Origin's engine over one designed by Aerojet Rocketdyne. It's unlikely the ULA would reconsider Aerojet's engines, they added.