As Missile-Defense System Deploys, Some Eye Directed-Energy Options

Sea Power, Nov 2004 by Roth, Margaret

Twenty-one years after President Ronald Reagan jarred the world with his notion of an omnibus $26 billion missile-defense program, the U.S. military services are deploying the first elements of a planned multilayered defense scheme intended to protect the United States, some allies and forces on the battlefield from missile attack.

Against a political and technological backdrop far different from that of the Reagan era, missiles are being emplaced - most recently in Alaska in late September - to activate a small initial system this fall in the western Pacific, Alaska and California. Today's system does not have the breadth or dazzle of Reagan's "Star Wars" concept, and the Pentagon's missile strategists lack a large, well-known adversary such as the Soviet Union to plan against. Instead, the Missile Defense Agency is more worried about missile threats from terrorists or rogue nations such as North Korea.

But contemporary strategists have a huge advantage. They are not restrained by the 1972 Anti-Ballistic Missile Treaty, which prohibited the testing or deployment of a ballistic-missile defense system. President George W. Bush pulled the nation out of the treaty in 2001.

Also, the new system has not received the intensive press scrutiny that was regular fare in the days of Star Wars. Eager to rattle the Soviets, Reagan unveiled his program with a dramatic prime-time announcement. Today, high-technology weapons are less of a novelty and the Pentagon is focused on the war in Iraq. The initial defensive system is being turned on without so much as a drum roll or a bugle's blare, just a series of press releases to call attention to it after more than two decades of controversy and debate.

Though the times and circumstances are different, the basic concept of an anti-ballistic missile network is little changed after more than two decades. An attacking missile would have to make its way through layers of sensors, command-and-control systems and defensive weapons to strike the United States or its allies.

The various layers of the defensive network would be attuned to the three phases in the flight path of the hostile missile:

* Boost phase, from launch to an altitude of up to 300 miles, typically lasts three to five minutes until thrusters burn out. Easier to track because of hot thruster exhaust. The ideal time to intercept and destroy a hostile missile.

* Midcourse phase lasts up to 20 minutes, during which thrusters are off, creating a predictable flight path. The missile may employ countermeasures such as decoys. Long midcourse flight time allows for the deployment of several interceptor missiles against it.

* Terminal phase begins when the missile warhead falls back into the atmosphere, and lasts 30 seconds to one minute.

The newly deployed missile-defense system is focused on the midcourse phase of flight. It comprises destroyers in the western Pacific specially equipped for long-range surveillance and track, and Ground-based Midcourse Defense (GMD) interceptors at Fort Greely, Alaska, and Vandenberg Air Force Base, Calif. It also includes a battle management system, ancillary radars and Defense Support Program satellites that constantly scan the Earth for signs of missile launches.

By 2006, this system will be expanded to 15 destroyers for surveillance and track tasks, three Aegis cruisers armed with SM-3 missiles and the deployment of as many as 16 GMD interceptors to Alaska and California.

In years to follow, this initial system will be bolstered with weapons designed to defend against missiles in the boost and terminal phases of flight. The oldest of these is the high-energy Airborne Laser (ABL), basically the Chemical Oxygen-Iodine Laser that dates to 1977, mounted on a Boeing 747-400, with infrared sensors to search and track, enemy missiles. Designed as a boost-phase defender, the ABL heats the metal skin of the attacking missile, causing it to explode. Still in development, it missed a 2004 target date for initial deployment.

The Kinetic Energy Interceptor (KEI) is designed to destroy incoming missiles by impacting them while their booster rockets are still burning. Initially viewed as a boost-phase weapon by the Missile Defense Agency, it now is seen as a dual-threat weapon for use in the boost and midcourse phases of a hostile missile's flight. Designed for mobile launchers, it is intended to be deployed close to hostile missile sites. The ground-based version is slated for deployment in 2010, with a sea-based model to follow three years later.

To combat missiles in their terminal phase, the military is working on several approaches:

* The Patriot Advanced Capability-3 is the most established element of U.S. ballistic-missile defenses. Acquired by the Army last year and used in Operation Iraqi Freedom, the surface-to-air guided-missile system is considered the best defense against short-range missiles.

* The land-based Terminal High-Altitude Area Defense, a reconfiguration of the Theater High-Altitude Area Defense system begun in 1992, is aimed at short- and medium-range ballistic missiles transitioning from mid-course to the terminal stage, either inside or just outside the atmosphere. The launchers are truck-mounted and can be rapidly airlifted worldwide in a C-130.