Reading about BE-4 delays, and something I’ve always wondered is why doesn’t/didn’t ULA develop its own engines?

Obviously, it’s too late now, but relying on a third-party for the most important part of your business seems like a mistake.

Rocket engines aren’t really a commodity item. The design of a rocket is closely intertwined with the engine.

It worked pretty well for a while, but even 10-12 years ago tensions with Russia were starting to flare and it should’ve been obvious that relying on them to supply a strategic asset was shortsighted.

Then, they contract a company in Blue Origin that has never developed an engine or been to orbit and is likely to become their competitor in the future.

Not that AeroJet would’ve done any better either.

All the while SpaceX is showing off what they’re capable of, bringing a clean sheet design into operation in less than a decade.

And at that point why not do it themselves?

All the New Space companies are developing their own engines these days: SpaceX, Rocket Lab, Blue Origin, Astra, and Relativity are all building engines in-house.

Many of these engines aren’t in the same class as what ULA requires, but with the resources that Lockheed/Boeing/ULA possess it should’ve been possible to do it themselves and they wouldn’t be in the position they’re in today.