Integrated Hypersonics - DARPA Tries Again

Integrated Hypersonics - DARPA Tries Again:
If at first you don't succeed, make it harder then try again. That seems to be the premise behind the US Defense Advanced Research Projects Agency's new Integrated Hypersonics (IH) program.
IH is a follow-on to DARPA's Falcon program, which failed in two attempts to fly the HTV-2 hypersonic glider. So much of a follow-on, in fact, that the IH program is to begin with a third flight of the HTV-2.
The new program is planned to culminate in 2017 with the flight of the Hypersonic X-Plane (HX), to demonstrate technology not only for a prompt global strike weapon, but potentially hypersonic aircraft missions "such as time-critical, survivable transport", says DARPA.