My dad was a member of that project team @ the skunk works.
I’ve read a few books about that stuff.
Legendary engineers and technicians and pilots.
Marlboros, slide rules, and pencil on vellum.
You do know he’s not legally allowed to tell you anything and, If he’s still alive, is libel; you need to understand you can be prosecuted, if they chose; this assumes your dad was not joking at the time and that such a thing still exists and is operational.
Right now you have only hearsay knowledge, not actually. But I’d keep that to yourself.