DARPA Falcon Project

[3][4] The HTV-3X Blackswift, derived from HTV-3, was a technological demonstrator of the HCV which would take off from a runway and accelerate to Mach 6 (7,400 km/h; 4,600 mph) before completing its mission and landing again.

The X-20 Dyna-Soar in 1957 was the first publicly acknowledged program—although this would have been launched vertically on a rocket and then glided back to Earth, as the Space Shuttle did, rather than taking off from a runway.

Originally, the Shuttle was envisaged as a part-USAF operation, and separate military launch facilities were built at Vandenberg AFB at great cost, though never used.

[6] According to Henry F. Cooper, who was the Director of the Strategic Defense Initiative ("Star Wars") under President Reagan, spaceplane projects consumed $4 billion of funding in the 1970s, 1980s and 1990s (excluding the Space Shuttle).

[8] The HyperSoar was an American hypersonic aircraft project developed at Lawrence Livermore National Laboratory (LLNL).

[12] In parallel, some work was still dedicated to the conceptual development of a Hypersonic Cruise Vehicle (HCV) that would be able to fly 9,000 nautical miles (17,000 km) in 2 hours with a payload of 12,000 lb (5,500 kg).

The Blackswift was derived from the HTV-3 and proposed a technological demonstration of a reusable aircraft capable of hypersonic flight designed by the Lockheed Martin Skunk Works, Boeing, and ATK.

He told the USAF website, I will also be communicating to Lockheed Martin and Pratt & Whitney on how important it is that we get the technical plan in place ...

Walker also stated, We need to fly some hypersonic vehicles—first the expendables, then the reusables—in order to prove to decision makers that this isn't just a dream… We won't overcome the skepticism until we see some hypersonic vehicles flying.In October 2008 it was announced that HTV-3X or Blackswift did not receive needed funding in the fiscal year 2009 defense budget and had been canceled.

According to a DARPA spokesman, "When the onboard system detects [undesirable or unsafe flight] behavior, it forces itself into a controlled roll and pitchover to descend directly into the ocean."

[26] Initial reports indicated it purposely impacted the Pacific Ocean along its planned flight path as a safety precaution.

DARPA has now changed its focus for the program from global/strategic strike to high-speed tactical deployment to penetrate air defenses and hit targets quickly from a safe distance.