You never heard about it. I am a huge fan of black budget projects. I always hope that the US military use it often. The F-117,SR-71 and B-2 bomber were former black budget projects
Since it’s called “black budget”, I’m glad that I, and most of the public at large, haven’t heard about it. ;o)
Keep me informed of the latest black budget projects of which you are aware. They are fascinating...