Hypersonic Cruise Vehicle
Force Application and Launch from CONUS (FALCON)

The Prompt Global Strike (PGS) Mission Needs Statement (MNS) established the requirement for rapid conventional strike worldwide to counter the proliferation of weapons of mass destruction and provide a forward presence without forward deployment. In December 2002 the DepSecDef directed the Air Force and Defense Advanced Research Projects Agency (DARPA) to establish a joint program office to accelerate the Common Aero Vehicle (CAV) effort to meet this requirement. This joint program has been named Falcon and was focused on the development and transition of more mature technologies into a future weapon system capable of delivering and deploying conventional payloads worldwide through space. As a result of FY05 Congressional language, the Falcon portion of the CAV program was restructured by DARPA and the Air Force to ensure it met the intent of Congress. Within the Falcon program, CAV has been redesignated the Hypersonic Technology Vehicle (HTV) and all weaponization activities have been excluded from Falcon.

The Government's vision of an ultimate prompt global reach capability (circa 2025 and beyond) is engendered in a reusable Hypersonic Cruise Vehicle (HCV). This autonomous aircraft would be capable of taking off from a conventional military runway and striking targets 9,000 nautical miles distant in less than two hours. It could carry a 12,000-pound payload consisting of Common Aero Vehicles (CAVs), cruise missiles, small diameter bombs or other munitions. The Government is interested in innovative HCV concepts that utilize novel technologies that mitigate heat load and extend range. Such innovative concepts could enable effective global reach missions and potentially provide the first stage of a two-stage access to space vehicle.

In FALCON Phase I Task 2, contractors will develop conceptual designs, concepts of operations, and a demonstration plan and identify critical technologies for the Hypersonic Weapon Systems portion of the program, which includes the Common Aero Vehicle, the Enhanced Common Aero Vehicle, and the Hypersonic Cruise Vehicle. The Common Aero Vehicle will be an unpowered, maneuverable, hypersonic glide vehicle capable of carrying approximately 1,000 pounds of munitions, with a range of approximately 3,000 nautical miles. The Enhanced Common Aero Vehicle would be a more advanced design that offered substantially greater range and improved maneuverability. The reusable Hypersonic Cruise Vehicle will be an autonomous aircraft capable of taking off from a conventional military runway and striking targets 9,000 nautical miles distant in less than two hours.

The DARPA/Air Force vision for FALCON is to develop, by 2025, a reusable hypersonic cruise vehicle that could take off from a conventional military runway and strike targets 9,000 nautical miles away in less than two hours. Flying at speeds up to eight times the speed of sound (Mach 8), the hypersonic cruise vehicle would carry a 12,000-pound payload comprising several unpowered, maneuverable, hypersonic glide vehicles called common aero vehicles; cruise missiles; small diameter bombs or other munitions. Each common aero vehicle would carry approximately 1,000 pounds in munitions.

The demonstration common aero vehicle system will be able to fly 3,000 nautical miles in approximately 800 seconds and deliver a 1,000-pound penetrator munition. An enhanced version of this demonstration system will be able to fly 9,000 nautical miles in approximately 3,000 seconds. The common aero vehicle and its enhanced version will also be able to "turn" to hit targets up to 800 and 3,000 nautical miles, respectively, off a straight trajectory. For the most part, common aero vehicles require the same technologies as hypersonic cruise vehicles, but also need a more rigorous thermal protection system to prevent their payloads from melting at re-entry speeds as high as Mach 25. By comparison, the hypersonic cruise vehicle will return to its base at speeds of approximately Mach 3-4.

FALCON Phase I, Task 2 contractors will receive between $1,200,000 and $1,500,000 each for their Phase I effort. Task 2 contractors are listed below. An additional award is under consideration. On 11/25/03: An additional Task 2 contractor was awarded funding, for a total of four Task 2 efforts.

• Andrews Space Inc., Seattle, Wash.
• Boeing Co., St. Louis, Mo.
• Lockheed Martin Corp., Lockheed Martin Aeronautics Co., Palmdale, Calif.
• Northrop Grumman Corp., Air Combat Systems, El Segundo, Calif. Northrop Grumman's FALCON program team is led by its Integrated Systems sector, but includes significant roles for the company's Mission Systems sector, Reston, Va., and Electronic Systems sector, Baltimore. The team also includes subcontractors Aerojet-General Corporation, Sacramento, Calif.; Space Works, Atlanta, Ga.; Textron Systems, Wilmington, Mass.; HITCO Carbon Composites, Gardena, Calif.; and Pratt & Whitney, East Hartford, Conn.

DARPA was responsible for overall program management of the FALCON program. DARPA manages the program, with the Air Force Space Command Space and Missile Systems Center providing a deputy program manager. Representatives from Air Force Space Command Space and Missile Systems Center/Detachment 12, Air Force Space Command DR and the Air Force Research Laboratory provide technical assistance and support in conducting milestone reviews.

Hypersonic aerodynamics research is critical to the Air Force's renewed interest in space operations. The size and weight of a hypersonic vehicle, and thus its flight trajectory and required propulsion system, are in large part determined by aerodynamic considerations such as boundary layer transition, shock-boundary layer interactions, drag, and airframe propulsion integration. A major research area of interest is high-speed boundary layer transition and control. Quiet wind tunnel research, stability experiments/ theory/ simulation, secondary injection control methods, and shock-dominated flow physics are all areas of interest. Another major area of interest is heat transfer as it relates to high speed aerodynamics. Gas/ liquid/ solid interface physics, microchannel flow physics, and novel approaches to cooling are all areas of interest.

Unsteady aerodynamics is a key element in the development and optimization of future Air Force weapon systems. Because these systems are unmanned, they can maneuver at extremely high rates, producing very dynamic forces on the aircraft body. Thus, research areas of interest include understanding the basic mechanisms present in time-dependent aerodynamic flows of all types, separated flows, separation control, circulation control, and vortical flows. Low-order flow modeling approaches that lead to adaptive control methods are desired. Internal and external flow tailoring for aerodynamic shape change is of interest. Nonlinear aero-structure interaction research, including flow control approaches for suppression of destructive flow-structure interactions, is also of interest. Aero-acoustics research, especially as it applies to airframe noise or sonic fatigue, would also be considered a part of the aero-structure interaction subthrust.

The unsteady aerodynamics and hypersonics research program within the Aerospace and Materials Directorate is focused on providing the fundamental fluid mechanics research base for these future systems. Through a balance of experiments, analytical modeling approaches, and numerical simulations of the relevant flow physics, a fundamental understanding of the basic fluid flow fields associated with future complex configurations is achieved. This increased knowledge base will provide flow field prediction methods and flow control approaches that, in the short-term, will reduce the weight and cost of future systems, and in the long-term, will enable completely new, revolutionary vehicle designs which are unacceptable today due to aerodynamic performance constraints.