I’m thinking this will cost way, and I mean way more than just $35 million.
Of course it will.
It’s probably $35 million for lab work or bench scale experiments.
As a rule of thumb, pilot / demonstration work costs 10X that. Then commercial deployment costs 10X that.
The success rate going from lab work to pilot is 10%. Then the success rate going from pilot / demonstration to commercial deployment is 10%.
This is true for all new technologies.
It’ll be $35M PER ENGINE. By comparison, SpaceX’s Raptor is a methalox engine with a nominal cost of ~$1M per engine with Elon’s desire to scale production to a point where the cost comes down to ~$250K. Nuclear propulsion was tried and was exceptionally effective, but electric engines aren’t going to produce the TWR required to get any meaningful payload into space. They’re really only useful in vacuum.