Amid SR-72 Rumors, Skunk Works Ramps Up Hypersonics | Defense content from Aviation Week
skunk Works is believed to be planning the start of FRV development next year, with first flight targeted for 2020. The FRV will be around the same size as an F-22 and powered by a full-scale, combined-cycle engine. However, in the run-up to the demonstrator development, Lockheed is thought to be testing several discrete technologies in a series of ground and flight tests.
According to information provided to Aviation Week, one such technology demonstrator, believed to be an unmanned subscale aircraft, was observed flying into the U.S. Air Force’s Plant 42 at Palmdale, where Skunk Works is headquartered. The vehicle, which was noted landing in the early hours at an unspecified date in late July, was seen with two T-38 escorts. Lockheed Martin declined to comment directly on the sighting".