This company is located in Indianapolis, and is a subsidiary of RR North American Technologies Inc.

It has developed a so-called “Hyper Mach” turbojet engine for vehicles with speeds from Mach 3 to Mach 5. This is the Lockheed RATTLRS.

“RR YJ-102R model engine”

-Curiously the RATTLRS vehicle has nacelles similar to those of the SR-71. We can see it in the picture behind the engine.