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Sea-Based Missile Defense System Shows Promise

The U.S. missile defense system is an intricate interweaving of various missile-interceptor systems, supported by advanced radars and satellite sensors.

There is sharp debate about its cost and its capabilities, but the system has seen meaningful progress at sea, says Lt. Gen. Henry Obering, director of the Pentagon's Missile Defense Agency.

"The furthest along that we have today is probably our Aegis sea-based component," Obering says. "It has been through some pretty good operational testing to explore all of its envelope — or quite a bit of its envelope — of operation."


The Origins Of Aegis

The U.S. Navy began the development of the Aegis combat system more than 30 years ago. Essentially, it was a marriage of advanced radar and signals capabilities with a variety of guided missiles deployed on cruisers and destroyers. Their task: Defend aircraft carriers and the carriers' battle group.

When the Bush administration decided to make a big push for missile defense, it figured that the missiles the Aegis ships were using against aircraft and other ships might be modified as missile interceptors. The key was the ship's advanced radars, says Lt. Cmdr. Andrew Bates, the ship's former combat systems officer.

"This is the trademark octagonal array for the SPY-1 radar," Bates says. "Its military designation is SPY, so obviously it's pronounced 'spy.' It's a happy coincidence."

The SPY-1 radar panels are positioned on both the port and starboard sides of the ship, as well as facing fore and aft. They give the ship 360-degree eyes to watch the sea and skies.


One ship, the Lake Erie, is on alert for a test missile attack, and the plan is to launch its own missiles, known as SM-2s, against the attacker.

The ship's radar illuminators will guide the missile interceptors to the attacking missiles, Bates says.

"When that missile is heading toward its target, it's receiving uplink commands from the Aegis weapon system," Bates says. "But that final bit of guidance that it gets just prior to intercept comes from these illuminators, which will point at the target, shine a beam of RF energy onto that target. The reflection from the RF energy off of that target will be picked up by the missile and will be used to guide it in on its final stage."

Dry Runs And Dress Rehearsals

In the three days before the actual missile flight test, the Lake Erie crew has been through two dry runs and one dress rehearsal that simulate missile attacks. Much of the key activity takes place in the darkened Combat Information Center. What little light there is comes from the glow of computer and video screens.

"During the shipboard countdown, we are taking the system to a higher and higher state of readiness, which is what we'd do if we were coming upon a vulnerability window where we had gotten intelligence that a launch may occur," Bates says. "At a certain point, we'll get to basically a stable sit-and-wait type of situation. The system's set up correctly. It's in a high state of readiness, and now the crew and the sailors here in CIC are looking for any indications of a ballistic missile launch."

The Lake Erie is the same ship that in February successfully shot down a disabled U.S. spy satellite carrying half a ton of toxic fuel that was threatening to fall out of orbit.

The Lake Erie's missile-defense system was not designed for that mission, but with modifications, the Missile Defense Agency determined it could do the job. In a radio hookup between the Pentagon and the Lake Erie, Rear Adm. Brad Hicks explains the difference between the satellite shot and the upcoming test flight.

"The satellite — we had a predicted time we were going to intercept it," he says. "We picked the time where we wanted to intercept it to optimize the probability of success. So the mission was totally different."

The satellite was 130 miles above the earth, traveling at more than 5 miles per second. But the missile to be intercepted in Lake Erie's flight test will be only 12 miles high, moving at about a quarter of that speed.

The Day Of The Flight Test

On the bridge of the ship the day of the test, Cmdr. Rich Martel, Lake Erie's executive officer, recalled February's satellite shot.

"We knew we should expect the satellite to pass through our area at this particular time," he says, "and in general on that day, the crew was very calm; we had done a lot of training. We were prepared."

As tension builds, Martel tells the crew that they can go out on the fantail, toward the stern of the ship, to watch the missile launch.

"No personnel on the flight deck or the missile deck, only on the fantail," he says. "In the event that the missile, once it takes off, self-destructs, all personnel should take cover against the bulkheads or inside the skin of the ship from the fantail. That's all. Don't give up the ship."

Tension continues to build, and then on the internal net comes "fireball" — the code word for the launch of a hostile missile.

Intercepted And Destroyed

Bates says initial indications are that the attacking missile, launched 180 miles away, has been destroyed.

"We could see an explosion around the first missile that was launched," he says. "And at the same time that I visually saw the explosion, I heard over the internal nets, the missile system supervisor say, 'Mark India,' so mark intercept."

Later, Hicks, speaking from the Pentagon, pronounces the flight test a success.

"Both SM-2s intercepted the target and destroyed it," he says. "We fired two to improve our probability of success, knowing that it's a terminal engagement. And they fired within a second-and-a-half of each other."

The Lake Erie has successfully tested SM-2 missiles against short-range missile attacks in the atmosphere and has destroyed medium-range missiles during an attack using the SM-3. Even sharp critics of the Missile Defense Agency, like Philip Coyle of the Center for Defense Information, acknowledge that sea-based missile defenses do show some promise.

"The Navy has had a greater success rate in terms of successes where they've done flight intercept tests," Coyle says. "They've had a greater success rate than the big ground-based system has had."

Worldwide Deployment

The Navy is already deploying this missile-defense system on more of its cruisers and destroyers, for use, Lake Erie's Capt. Ron Boxall says, anywhere it is needed.

"As you look at the proliferation of ballistic missiles throughout the world, I think it's myopic to view any specific country as the target," he says. "Our job is to produce the capability and go out and make it employable and available to the fleet and combatant commanders."

Hicks says 15 ships have anti-missile capabilities now — most are operating in the Pacific, with a few deployed in or near the Middle East.

"We have now taken a look at what we require for the Fifth Fleet in the Arabian Gulf and we, in fact, have assets in theater now," Hicks says. "And we've also had our first asset that operated in the eastern Mediterranean."

The U.S. missile defense is about to go global, with the inclusion of ground-based missiles stationed in Europe.

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