As the U.S. Air Force prepares for its second attempt to launch Darpa’s Hypersonic Technology Vehicle 2 (HTV-2), the research agency has issued an interesting video depicting the planned mission on August 11.
The HTV-2, designated HTV-2b according to a close up image of the vehicle taken earlier today by Bill Hartenstein, is designed to demonstrate the high lift-to-drag aerodynamics and high-temperature materials needed for sustained hypersonic flight, with the goal of validating technology for a vehicle able to reach anywhere in the world in 60 min.
The second HTV-2 incorporates a more robust flight control system to counter the issues which led to the loss of the first vehicle, nine minutes into the flight on April 22, 2010. The revised control system incorporates changes to the center of gravity to reduce the lateral/directional coupling which occurred on the first flight, as well as adaptations to allow the vehicle’s nitrogen-gas reaction control system (RCS) to be used for yaw control in the atmosphere – as well as in space. The video clearly shows the RCS hard at work during the simulated cruise phase of the flight. The graphic (below) shows all the planned phases of the test flight while the video clip includes all the excerpts indicated by the blue-colored call-outs
Here are some ‘fun facts’ about HTV-2 from Darpa’s Twitter account:
- Following release from the Orbital Sciences Minotaur IV booster the HTV-2 will glide at more than 13,000 mph.
- This equates to 3.6 miles per second.
- Surface temperature will reach in excess of 3,500 deg F.
[Editor's note: see an update from Guy here
on the test.]