Air Defense: American SM-3 BMD System Goes to War


April 29, 2024: The April 14 Iranian missile and UAV attack on Israel was an expensive and spectacular failure because Israel had prepared for it over the previous twenty years. Back in 2000 Israel put its Arrow BMD (Ballistic Missile Defense) system into service. Since then there were only two opportunities to use it. The first was in 2017 when Syrian air defense units fired a Russian S-200 anti-aircraft missile at Israeli fighter-bombers that had carried out an attack in Syria and were flying back to Israel. The S-200 missed the Israeli aircraft because the aircraft had countermeasures, and so kept on going towards Israel. The Arrow target detection spotted the S-200 and decided it was a missile entering Israeli air space and must be dealt with. An Arrow missile was fired and an S-200 missile was destroyed. Many Israeli air defense officials believed that Arrow was more expensive than it was worth. Arrow was also used against Iranian ballistic missiles aimed, by Yemen Shia rebels, at southern Israel in October and November 2023. Arrow worked but it was too expensive and there were less expensive solutions like David’s Sling, which used Israel’s successor to American Patriot missiles.

The U.S. Navy had two warships off the Israeli coast when Iran launched everything it had against Israel. The American warships used the SM-3 BMD system to destroy several of the incoming Iranian ballistic missiles. This was the first combat use of the Navy SM-3.

In 2008 SM-3 was also used to destroy a malfunctioning U.S. spy satellite. A U.S. Navy cruiser armed with SM-3s was ordered to destroy the useless American satellite. First it used its Aegis radar to locate the 14-ton Lacrosse satellite traveling in an erratic orbit 220 kilometers above the ocean, with the cruiser below, then it launched an SM-3 missile at the large satellite which was about the size of a small bus. The Aegis radar and fire control system on the cruiser predicted where the satellite would be so the SM-3 missile hit it. This was not an easy to hit target, because the satellite was out of control and moving erratically. The orbit had to be predicted at least to the point where the cruiser could position itself under that orbit. But that was a good thing if this anti-satellite weapon was to be used again. In wartime, an enemy satellite might try to maneuver to avoid a shot from an Aegis equipped warship.

The February 22nd shot took six weeks to plan, mainly because there were so many unknowns. Now, many of those unknowns are known and another shoot-down can be carried out much more quickly. How quickly remains a secret.

There were other surprises as well. When the 20 pound missile warhead hit the satellite, there was an unexpected explosion as the hydrazine fuel of the satellite ignited. The flames burned for over twenty seconds. The impact of the inert warhead, which is just a warhead shaped hunk of metal, was more destructive than anticipated because it broke the satellite up into more and smaller pieces. That meant the fragments burned up while entering earth’s atmosphere and there was nothing left to hit the ground. This process provided an impressive light show for those who knew when and where to look in a night sky. Because of this event the navy was able to establish procedures for possible future satellite take-downs and ran some shipboard drills to test these new procedures.

So far, the Aegis system has knocked down 85 percent of the missiles fired towards it. To do this, the navy modified its Standard anti-aircraft missile system to knock down ballistic missiles. This system, the RIM-161A, also known as the Standard Missile 3 or SM-3, has a range of over 500 kilometers and max altitude of 160 kilometers. The satellite destruction took place at an altitude of 220 kilometers. This was a previously undisclosed capability of the Aegis anti-missile system.

The Standard 3 is based on the failed anti-missile version of the Standard 2, and costs over three million dollars each. Standard 3 has four stages. The first two stages boost the interceptor out of the atmosphere. The third stage fires twice to boost the interceptor farther beyond the earth's atmosphere. Prior to each motor firing it takes a GPS reading to correct the course for approaching the target. The fourth stage is the 20 pound LEAP kill vehicle, which uses infrared sensors to close on the target and ram it. The Aegis system only operates from cruisers and destroyers that have been equipped with the special software that enables the AEGIS radar system to detect and track incoming ballistic missiles. The plan was to fire two or three missiles at the satellite, to insure that one hit. Since the satellite will be destroyed at a low altitude, the fragments will quickly fall into the atmosphere and burn up. A Chinese anti-satellite test in 2007 was done 850 kilometers up, and nearly all those fragments are still in orbit being a threat to other satellites.

The U.S. Navy has also been working on launching various types of satellites from its submarines. But solid fuel SLBMs (sea launched ballistic missiles) can only put a ton or less into orbit. Smaller satellites can be put in orbit quickly using SLBMs. While the U.S. Air Force lays claim to all things space, the U.S. Navy is quick to demonstrate that sailors are able to operate up there as well. And maybe the navy should get more of the billions being spent on space operations.




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