First Glide Test Expected In 2007
For an aircraft to achieve hypersonic speeds, ranging from 6,000
to 15,000 mph (Mach 9 to Mach 22), and reach altitudes between
100,000 to 150,000 feet, it needs an airframe structure designed to
survive intense heat and pressure. Such technology is in
development by scientists and engineers with the Falcon hypersonic
technology vehicle, or HTV, program.
Started in 2003, the joint Air Force and Defense Advanced
Research Projects Agency endeavor consists of two 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 program include NASA, the
Space and Missile Systems Center, Sandia National Laboratories
(below) at New Mexico's Kirtland AFB and the 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 here, 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,
the Falcon HTV-1 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 is set to complete its inaugural voyage over the
Pacific Ocean. Attaining Mach 19, the vehicle will briefly exit the
Earth's atmosphere and re-enter 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, it
re-enters the atmosphere like the space shuttle, and in the latter
stage, it flies like an aircraft," Mr. Partch said. "It is an
interesting mix of challenges and technologies."
For the second 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 and then finish its one-hour plus mission over the Pacific
Ocean.
On the other hand, the third and final Falcon HTV, slated for
2009, will be a departure from the previous demonstrations. The
reusable hypersonic glider will lift off from NASA's Wallops Flight
Facility at Wallops Island, VA, and then more than an hour later,
be recovered in the Atlantic Ocean.
In addition, the HTV-3, flying at Mach 10, 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,"
Mr. 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 more than 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
multilayer insulation is being created for long flights.
Researchers are also designing tools to enhance HTV navigation and
maneuverability for robust aerodynamic performance.
"We are now starting to build the HTV-1's critical flight
hardware components," Mr. Partch said. "The entire test vehicle
will be integrated at the Lockheed Martin Corporation's facility in
Valley Forge, PA."
With its initial flight vehicle project progressing rapidly, the
Falcon HTV program is poised to meet the challenges of achieving
unprecedented hypersonic technology validation in flight and
demonstrating operationally responsive space lift. The results of
these three experimental flights will have a significant impact in
the development of future military delivery platforms and launch
systems.
(Aero-News thanks Michael P. Kleiman, Air Force Research
Laboratory Space Vehicles Directorate Public Affairs)