The HTV-2 is designed to be able to strike anywhere in the world within 60 minutes. To be able to achieve this feat an aircraft would need to fly at 13,000MPH. The HTV-2 would be launched and successfully placed into desired trajectory by using a separate vehicle. After successfully separating from the launch vehicle the HTV-2 would transition into MACH 20 aerodynamic flight.
On August, 11, 2011, the HTV-2 was launched and separated from the launch vehicle, Minotaur IV. More than nine minutes of data was captured before an anomaly caused loss of signal. This anomaly has puzzled scientists and they are trying to understand what went wrong. It appears that the HTV-2 crashed into the Pacific Ocean along its planned flight plan.
“Here’s what we know,” said Air Force Maj. Chris Schulz, DARPA HTV-2 program manager and PhD in aerospace engineering. “We know how to boost the aircraft to near space. We know how to insert the aircraft into atmospheric hypersonic flight. We do not yet know how to achieve the desired control during the aerodynamic phase of flight. It’s vexing; I’m confident there is a solution. We have to find it.”
There are a couple of technical areas of concern that DARPA are working on to get the HTV-2 operational. The areas are aerodynamics, aero thermal, guidance, navigation and control. When DARPA do manage to solve these vexing problems it is certainly going to make the US defence that much more powerful than it is already.