KIRTLAND AIR FORCE BASE, N.M., 26 Jan. 2006. Engineers from the U.S. Air Force and Defense Advanced Research Projects Agency (DARPA) are building an airframe structure designed to survive the intense heat and pressure of hypersonic speed, ranging from 6,000 to 15,000 miles per hour (Mach 9 to Mach 22), and reaching altitudes between 100,000 to 150,000 feet.
Such technology is currently being developed by scientists and engineers serving with the Falcon Hypersonic Technology Vehicle program.
Initiated in 2003, the joint Air Force and Defense Advanced Research Projects Agency endeavor consists of two distinct objectives: to develop hypersonic technology for a glided or powered system and advance small, low cost, and responsive launch vehicles.
Other partners participating in the demonstration program include the:
* National Aeronautics and Space Administration,
* Air Force Space and Missile Systems Center,
* Sandia National Laboratories, and
* Air Force Research Laboratory's Air Vehicles and Space Vehicles directorates.
Both AFRL organizations have been working on the project's hypersonic technology vehicle portion, with Space Vehicles (located at Kirtland Air Force Base, N.M.) specifically focusing on technologies for the glided system.
"We have made great progress and are on track for the first glided hypersonic test vehicle flight in 2007," said Russ Partch, Falcon Hypersonic Technology Vehicle-1 project manager. "It will enable a revolutionary capability to quickly respond to events anywhere around the world."
Planned for a less than one-hour flight in September 2007, the Falcon HTV-1 will complete its inaugural voyage in the Pacific Ocean. Attaining Mach 19 speed, the glided air vehicle will briefly exit the Earth's atmosphere and reenter flying between 19 and 28 miles above the planet's surface. Demonstrating hypersonic glide technology and setting the stage for HTV-2 represent the primary focus of the lower risk/lower performance initial flight.
"This is a very unique vehicle. During the early part of the flight, it acts like a spacecraft. In the middle phase, the HTV reenters the atmosphere like the Space Shuttle, and in the latter stage, it flies like an aircraft," said Partch. "It is an interesting mix of challenges and technologies."
For the second glided demonstration, scheduled for 2008 or 2009, the Falcon HTV-2 will feature a different structural design, enhanced controllability, and higher risk/performance factors during its high-speed journey. Like its predecessor, the system will reach Mach 22 speed, and then finish its one-hour plus mission in the Pacific Ocean.
On the other hand, the third, and final, Falcon HTV, slated for flight in 2009, will be a departure from the previous two demonstrations. The reusable hypersonic glider will lift off from NASA's Wallops Flight Facility, Wallops Island, Va., and then over an hour later, be recovered in the Atlantic Ocean. In addition, the HTV-3, flying at a maximum of Mach 10 speed, will be designed to achieve high aerodynamic efficiency and to validate external heat barrier panels that will be reusable.
"The HTVs will prove technologies for global reach vehicles that can get a payload to the area of interest quickly in support of the joint warfighter," Partch said.
Currently, program staff at the Space Vehicles Directorate are helping develop a thermal protection system for the HTV structure to withstand 3,000-degree temperatures and incredible exterior pressures (25 times those experienced by the Space Shuttle). An important component of this critical technology, the all carbon aeroshell, must keep from being crushed or burned up in this environment. To keep the vehicle interior cool, an advanced multi-layer insulation is being created for long duration flights. In addition, researchers are designing tools for enhanced HTV navigation and maneuverability resulting in robust aerodynamic performance.
"We are now starting to build the HTV-1's critical flight hardware components," said Partch. "The entire test vehicle will be integrated at the Lockheed Martin Corporation's facility in Valley Forge, Pennsylvania."
With its initial flight vehicle project progressing rapidly, the Falcon HTV program is poised to meet, during the next three to four years, the formidable challenges of accomplishing unprecedented hypersonic technology validation in flight and demonstrating operationally responsive space lift. As such, the results of these three experimental flights will have a significant impact in the development of future affordable, adaptable, and responsive military delivery platforms and launch systems supporting the joint warfighter.
The project is based at the Air Force Research Laboratory, Space Vehicles Directorate. For more information, see www.vs.afrl.af.mil.
