The Problem with Iron Dome

The Iron Dome missile defense system has served Israel very well. But it does have a vulnerability that they might want to consider. It is expensive to operate. I believe the best counter measure would be to exhaust it, by overwhelming it with decoys.

1. A sufficient number of decoys will degrade Iron Dome's response, possibly enabling actual warheads to penetrate Israeli defenses.

2. Decoys are less costly to deploy than rockets carrying actual warheads. But they are just as costly to shoot down.

3. The money that the enemy saves can be used to produce more accurate guidance systems for the actual warheads. The increased cost of these devices can be justified by the increased likelihood of them actually striking their targets, thereby necessitating a smaller number of warheads.

4. Decoys can be smaller than other rockets, making them easier to store.

5. Decoys are lighter, making them easier to transport.

A corner reflector is a device, consisting of three reflectors, at right angles to one another, that reflects electromagnetic energy, such as light or a radar signal, back in the direction from which it came. Normally, when a radar beam strikes a target, most of the energy is scattered, while a very small portion is reflected back to the source. A corner reflector reflects a larger portion of the energy back to the source, making it look, on radar, like a much larger object than it really is.

A rocket that is little more than a toy, but equipped with a corner reflector, can appear to be a much larger object, such as one that might level a city block. If the Israelis see such a device being fired at them, they will go to a great deal of trouble to shoot it down.

You might think a corner reflector could be carried within a rocket, as long as the rocket is made of a material that the radar can penetrate. If radar energy can penetrate a substance, that does not mean the substance is transparent to the radar. As an analogy, light can penetrate frosted glass. But frosted glass is not transparent, because the light is scattered in the process. This scattering would render a corner reflector inoperable. In order to work effectively, the corner reflector must be visible.

However, a corner reflector has very poor aerodynamic properties, and would probably need to be covered for that reason, for it to be incorporated into a rocket. I believe the best approach would be to design the corner reflector in a shape that is suitable to be placed within a rocket, and then to cover it with a thin transparent material. I believe rigid polyethylene, approximately 1/8 inch thick, would be about right.

The shape I would recommend is a 5” diameter five pointed star, which presents interior right angles. This star would be approximately 5” high, and sandwiched between two DVD's, with the mirrored surfaces facing inward. The exterior surfaces of the star would also have to be mirror surfaces. A surface that is smooth, but which does not have an actual mirror surface, is basically a wasted effort. The star could be a piece of sheet metal that is bent into shape, or it could be made of aluminum foil. But it must be perfectly smooth. Aluminum foil that is glued to a piece of cardboard would not work, because it is likely to contain a lot of dimples, which would reflect the energy in the wrong direction.

The resulting structure would be a cylinder, which could be encased within a polyethylene tube. There would also be sufficient room in the center for a 1” diameter pipe, which would provide the rocket with structural integrity. I lack the expertise to design a rocket. But I believe a good rocket scientist could take my idea, and build on it.

There are counter measures Israel might employ. I won't go into them. But I will say that they would be very expensive. They would also take time. And you don't have a lot of time when you have a missile coming at you. Basically, I believe the technology favors those who fire rockets, rather than those who would defend against them.