As they work to implement the Department of Defense blueprint for transforming the United States’ strategic posture through greater military use of advanced technologies, Air Force officials are developing a hypersonic-glide vehicle capable of depositing 1,000 pounds of conventional weapons or other payload anywhere on earth within hours of launch from the United States.

The system, known as the Common Aero Vehicle (CAV), is designed to provide a global reach capability against high-value targets in a single or multitheater environment, while reducing response time from days and weeks to minutes and hours, even when there is little or no U.S. presence in the targeted region.

When matched with a responsive launch program, the CAV could “provide a truly transformational capability to anywhere in the world,” General Lance W. Lord, commander of Air Force Space Command (AFSPC), told the House Armed Services Committee earlier this year. “This is the type of prompt global strike I have identified as a top priority in our space and missile force.”

While the CAV is still in the conceptual stage, with no established testing or development schedule, planners envision a vehicle that could be sent aloft either by an existing booster rocket or some other launch vehicle. From there, the unpowered glide craft would have a range of 9,000 nautical miles, providing global coverage from a U.S. launch site.

A key advantage of the CAV is that it could be maneuvered during flight, giving commanders flexibility and, unlike a ballistic missile, the ability to cancel a mission after takeoff. On the other hand, the risk that another country might mistake a recallable, conventionally armed CAV as a nuclear missile has raised concerns in Congress and led lawmakers to impose curbs on program development.

The CAV is related to, but separate from, a joint Air Force-Defense Advanced Research Projects Agency (DARPA) program called Falcon, which is exploring hypersonic technologies with the goal of developing a prompt global strike capability. (See MAT Volume 3, Issue 2, page 10.)

The Falcon technology demonstration program comprises two task areas, each of which is divided into system definition, design and development, and demonstration phases. Task I is focused on a small launch vehicle (SLV), while Task II involves hypersonic technology vehicles (HTV). After issuing initial contracts in 2003, the Air Force and DARPA last year awarded design and development contracts for the HTV to Lockheed Martin, and for the SLV to Air launch, Lockheed Martin, Microcosm and Space Exploration Technologies.

Falcon is currently scheduled to achieve first flight of an HTV in fiscal 2007, with additional demonstration flights in 2008 and 2009. Developers plan to research such technological topics as durable high-temperature metals, enhanced thermal protection systems, advanced guidance, navigation and control, and communications.

In the near term, the CAV could be used with a conventional rocket to provide a limited capability to put high-priority targets at risk. A variety of launch options could be available in the mid-term, around 2018, depending, in part, on the results of the Air Force’s analyses of alternatives for prompt global strike and operationally responsive spacelift. Other possibilities for employing the CAV at that time include using a ground- or air-launched SLV, or a hybrid reusable launch vehicle.

Misidentification Risks

The CAV program has encountered some skepticism in Congress, especially in the Senate, which eliminated funding for the project in the 2005 defense appropriations bill. The final defense spending measure included a total of $29.1 million for the program, which represented about two-thirds of the original request.

While approving funds for the program, however, lawmakers also expressed continuing concern about a lack of safeguards to ensure against the danger that other nuclear nations might misinterpret the intent or use of the Falcon/CAV programs. As a result, conferees required that funds be used only for the development of hypersonic technologies for non-weapons-related research, such as micro-satellite or other satellite launch requirements.

The funding bill also directed that no money be used to develop or test a CAV variant that includes a nuclear or conventional weapon or to develop a CAV for launch by an ICBM or SLBM. Appropriators said they would consider expanding the scope of the program, however, if safeguards could be negotiated with other countries.

The Air Force commissioned two studies looking at the issues of misidentification and miscalculation involving CAV. A recent paper addressing congressional concerns outlines a number of steps for reducing confusion and attending risks of nuclear confrontation, with a specific focus on allaying Russian fears about U.S. development of a conventional ballistic missile option.

According to AFSPC spokesman Captain Joseph Macri, a package of tailored mitigating measures designed to ease international concerns about a CAV program might include:

• Establishing a conventional/nuclear firewall that would doctrinally separate a conventional-only capability such as the CAV from the existing nuclear capability embodied in the missile fields of Montana, Wyoming and North Dakota.
• Deploying CAVs only at coastal bases, thus allowing other countries to see that the vehicle was launched from a distinct location occupied only by conventional assets.
• Using trajectories for CAVs that would be clearly different from those for ballistic missiles.
• Creating a shared early warning system to increase openness with international partners.

“These and other related mitigation options would have to be carefully vetted for incorporation into a comprehensive, stability-enhancing regime consistent with U.S. government balancing of objectives in developing and fielding future CAV capabilities,” the recent Air Force paper states. “While no system can totally preclude all potential misinterpretations, the Department of Defense believes this risk can be managed to very acceptable levels.”

Military Utility

Despite such issues, Air Force officials say the CAV could be a valuable addition to the U.S. arsenal of the future.

An Air Force-commissioned military utility analysis (MUA), for example, found that CAVs could be the weapon of choice in a variety of military scenarios. While not ideal for every sort of target, it could be particularly useful in striking the most heavily defended targets, thus enabling bombers and other weapons to focus elsewhere.

The CAV’s timeliness and survivability would also offer significant advantages, the MUA report contends. With its high velocity and mobility, it would be virtually immune to defenses, thus enabling it to strike deep into enemy territory. In addition, it could be employed at the outset of a campaign to take out the hardest targets, even as other military assets were being transported to the area of hostilities.

With an impact speed of approximately 4,000 feet per second, the CAV would have massive penetrating power, making it a strong option for use against hardened underground bunkers when equipped with a 1,000-pound advanced unitary penetrator. Other munitions, such as the 250-pound small-diameter bombs, could be deployed by the CAV in flight to strike targets autonomously. The system could also carry intelligence, surveillance and reconnaissance payloads, such as small UAVs or unattended ground sensors.

To ease congressional concerns and demonstrate the potential value of a missile armed with conventional weapons, a key first step will be to “demonstrate the capability of a CAV-missile combination to execute precision conventional strikes,” Macri said. “Successful demonstrations that this new capability works in the field should help stimulate new thinking about its operational use in support of existing war plans and other demands.”

More broadly, backers say the system also holds out the promise of an enhanced U.S. deterrent capacity in a new strategic era. “While the United States has successfully achieved deterrence for over 50 years using our nuclear capabilities, we need to leverage non-nuclear deterrent capabilities in the future,” Macri said. “This ability, combined with forward-presence forces and a robust expeditionary force capable of rapid forward deployment with significant conventional firepower, will form such a significant threat that adversaries will be deterred from initiation or further escalation of hostilities.”