DARPA Hypersonic Vehicle Splash Down Confirmed

dtmos writes "DARPA has announced that its Falcon Hypersonic Technology Vehicle 2 flight on Thursday, 11 August, 'experienced a flight anomaly post perigee and into the vehicle's climb. The anomaly prompted the vehicle's autonomous flight safety system to use the craft's aerodynamic systems to make a controlled descent and splash down into the ocean.' 'According to a preliminary review of the data collected prior to the anomaly encountered by the HTV-2 during its second test flight,' said DARPA Director Regina Dugan, 'HTV-2 demonstrated stable aerodynamically controlled Mach 20 hypersonic flight for approximately three minutes. It appears that the engineering changes put into place following the vehicle's first flight test in April 2010 were effective. We do not yet know the cause of the anomaly for Flight 2.'"

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Mach 20 isn't really exotic in this context: don't think of it as a plane; it's more like a Reentry Vehicle for an ICBM warhead. The innovation is instead of following a ballistic trajectory (perhaps with minor maneuvering with an RCS), it glides aerodynamically. That gives it considerably more maneuverability, which would let it drop a bunch of bombs along the way, retarget late in flight, evade countermeasures like a fox, and perhaps even work as a rapid-deployment surveillance platform.

As far as air breathing aircraft go, we haven't progressed very well since the late 60s / early 70s. In that era, we came up with the Concorde (Mach 2 supercruise), and the SR-71 (Mach 3 on an engine that's built like a turbojet with reheat, but effectively operates as a ramjet at cruise speed). For practical aircraft, that's the best we've ever done. Prototypes like the X-43 and X-51 are pushing it farther, but they're only running a couple minutes at a time so far. Sustained flight at those speeds is really hard, so the Falcon's approaching it from the other end: bringing down the speed of a rocket-boosted vehicle instead of trying to raise the speed of an air-breather.

Unfortunately it's mostly a military toy since it's rocket-launched. Few peaceful applications are going to want to pay for an IRBM or ICBM per-use. The most we'll get out of it is knowledge about how to fly at these speeds which may come in handy if we get a practical scramjet working.