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"Americans Flying Rockets Are Not Terrorists!"

Copyright © 2003 Amateur Rocketry Society of America

Answers To The Department of Justice &
ATFE Anti-Rocketry Propaganda Campaign!

The Amateur Rocketry Society of America

Background Information

After the terrorist incident of September 11th, the United States Congress with the full support of the White House passed the Patriot Act and the Homeland Security Act. The Homeland Security Act has had a devastating affect on rocketry in the United States. It requires that American citizens obtain permits from the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATFE) in order to fly rockets consisting of cardboard tubes, plastic nosecones and fins. In order to obtain this permit, the applicant has to be finger printed, supply information for a background check and pay a $100 fee plus the costs of be finger printed by local law enforcement. In order to receive the permit the applicant has to show access to a federally approved explosive storage facility. Ironically, the propellant and rocket motors used are not explosives. As one would suspect, most people cannot obtain access to an explosive storage facility. Most residential neighborhoods are not keen on neighbors putting explosive magazines in their back yard and apartment managers are most definitely against them in apartments. Very few companies with federally approved explosive storage facilities are going to let "Joe Citizen" walk in off the street and use the company's explosive magazine.

The result of the Homeland Security Act has been thousands of Americans dropping out of hobby rocketry. This has been reflected by sales declines on the order of 70% to 80% for businesses selling hobby rocket motors, rocket kits, electronics and various other supplies. The law has also had a chilling effect on private university aerospace engineering courses that offer "hands-on" rocketry to students. These universities include MIT, Caltech, Syracuse, Stanford, Princeton, John Hopkins, Florida Institute of Technology and Embry-Riddle Aeronautical University.

In response to this over regulation of American universities and a harmless hobby, ARSA drafted a bill to provide an exemption for rocketry in the Homeland Security Act. The bill was refined and introduced by Senator Mike Enzi (R) from Wyoming on March 27, 2003.

Click here for the text of Senator Enzi's speech introducing his bill - S724.

Since the introduction of S724, the Department of Justice and ATFE have been feeding misinformation to the media and Congress in an attempt to defeat or severely weaken the bill. The Department of Justice's concerns and opposition to S724 were first publicly expressed in a letter written to Senator Hatch, chairman of the Senate Judiciary Committee. These concerns were amplified and expressed again by Senators Schumer and Lautenberg during a press conference on July 29, 2003.

Department of Justice Letter to Senator Hatch.

Click here of Senator Schumer's press release on S724

In response to the misinformation promoted by the ATFE and Department of Justice, ARSA has conducted research on each of the false claims. Below we present the facts on one these false claims.

Rocketry A Threat To Military Armored Vehicles?

The Department of Justice (DOJ) claims that amateur and hobby rockets can be used to make "light anti-tank" weapons with a range of up to five miles.

DOJ Letter: "These large rocket motors could potentially be adapted by terrorists for use in surface-to-air missiles capable of intercepting commercial and military airplanes at cruise altitude and for use in “light anti-tank” weapons capable of hitting targets from a range of nearly five miles."

Let's examine the case where a rocket is shoulder fired at a tank or other armored vehicle. In the analysis, we assumed the rocket was fired horizontally from a height of five feet off the ground. When something is fired horizontally, it accelerates towards the ground at a constant rate due to gravity. The rocket is not generating lift as it flies so the time to impact is independent of the horizontal velocity. In all cases, it hits the ground within 0.56 seconds and reaches a distance of three feet off the ground within 0.35 seconds from when it is fired. We picked rocket speeds typical of high power and amateur rockets and then increased the speed well into the supersonic and hypersonic range.

Unguided Rockets Fired At Tanks & Armored Vehicles
Range When Shoulder Fired
Table 1
Rocket Speed (mph) Range At 3 ft Off The Ground (Yards) Range To Hitting The Ground (Yards)
300 52 82
600 103 163
1,500 259 409
2,500 431 (0.24 miles) 681 (0.39 miles)
5,000 862 (0.49 miles) 1,362 (0.77 miles)

To put these numbers in perspective, the muzzle velocity of an M16 rifle ranges from 1,977 mph (2900 fps) to 2,182 mph (3200 fps) depending on the ammunition used in the gun. The amateur or high power rocket is going to have to travel at the speed of a bullet in order to have a range in terms of a fraction of a mile. For the rocket to even come close to one mile in range, it must travel at over 5,000 mph. To reach a distance of five miles when fired horizontally, the rocket would reach speeds so high that it would burn up in the atmosphere.

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Suppose the rocket is not fired horizontally, but in a ballistic arc towards a tank or a light armored vehicle such as a LAV-AT or LAV-25 (right). They are 98.4 inches wide and 251.6 inches long according to information provided by US Marine Headquarters. To hit the vehicle, the terrorist will need to know the precise range to the target. It is unlikely that the crew is going to radio this information to the terrorist. The range finder used in the M1 tank is accurate to within 33 feet. It is unlikely that the terrorist is going to have a better range finder. So, the first problem the terrorist will not be able to solve is, "What is the precise distance to the target?"

But, let's assume he finds out this information and that the vehicle is going to stay parked so he can get his shot off. To hit the target, the terrorist is going to have to launch the rocket at an precise angle so that it lands five miles away within the width of the vehicle. For the LAVs, the rocket must land within a 49.2 inch radius for a "kill". The M1 tank is wider so the rocket must land within a 72 inch radius. To hit that small of a target from five miles away, the rocket must be launched at an angle accurate to within 0.0012 degrees. This is physically impossible. When the effects of wind are taken into consideration, it is even more ridiculous. This is not surprising as the best engagement ranges for the M1 tank with its sophisticated equipment approached 2.5 miles during Desert Storm. Analysis clearly shows that the claim by the Department of Justice & ATFE that an unguided rocket can hit an armored vehicle five miles away is nonsense.

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Suppose the terrorist builds the rocket so that it actually generates lift or "flies" to the target and since it has already been shown that an unguided approach doesn't work, he adds a guidance system to it. What the terrorist has essentially built is a TOW missile (left). According to US Marine Headquarters, the TOW missile is 5.8 inches in diameter and has a length of 48 inches. It is guided to the target by the operator via wires deployed out the back of the missile. The TOW missile has a range of 2.33 miles and takes about 20 seconds to reach its target. But, this is not even half the five mile range a terrorist is supposed to be able to achieve. He must have more knowledge and capability than Hughes (missiles) and Electro Design Mfg. (launchers). The Department of Justice and ATFE claim that a terrorist can build an anti-tank missile out of high power rocketry or amateur rocketry parts with twice the range and capability of the TOW missile!

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Let's take a look at the capability of the newest, anti-tank rocket currently being produced for the US military. It is called the Line-of-Sight Antitank (LOSAT) missile (right). Lockheed-Martin will deliver 108 LOSAT missiles to the US Army at a total cost of $9.3 million by July 2004. Those missiles will go to the first tactical LOSAT unit, A Company of the 5-11th Parachute Infantry Regiment. The missile accelerates to 5000 feet per second and flies to its maximum range in less than four seconds. It weighs 174 pounds and is 113 inches long with a diameter of 6.4 inches. The LOSAT missile is a kinetic energy missile with no explosive warhead. It penetrates the armor of the target vehicle with a long-rod penetrator. LOSAT has a maximum range of 5,000 meters or 3.1 miles.As incredible as it may seem, the Department of Justice and ATFE claim that a terrorist can build an anti-tank missile out of high power or amateur rocketry parts with more range than the latest US military anti-tank missile just now going into production! According to them, the terrorist can "tinker" together an anti-tank missile with a range of 5 miles while the best the US military will be able to do next July is 3.1 miles.

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Suppose we forget about the five mile range and look at the possibility of making a simple "light armored" weapon using amateur or high power rocketry parts. What the terrorist would be making in this case is a rocket propelled grenade or RPG . On the left is shown a 40mm Heat RPG. Most Americans have seen these RPGs on CNN during reports on events in Iraq, Africa and other places. It has an effective range of 328 yards against moving targets, up to 547 yards against stationary targets and a maximum range of 1006 yards. While its appearance may strongly resemble something that could be made out of amateur or high power rocketry parts, that is far from the case.

First there is the warhead on the RPG. If the terrorist uses black powder or smokeless powder and metal fragments for the warhead, he will find it to be totally ineffective against light armor. He would need to create a "High Explosive Anti-tank" or "HEAT" warhead. It is much more complicated than a flying "pipe bomb". The nose of a HEAT warhead has an extended impact sensor. When it collides with the target's armor, it ignites a plastic explosive. The plastic explosive is shaped like a "lens' that focuses the explosive energy on a copper cone so that the momentum of the explosive is transferred to the copper. The cone's slope must be precisely made so that the speed of the blast on the cone surface is equal to the copper's speed of sound on the cone surface. If it is made right, the result is molten metal and hot gases focused into a narrow blast that cuts through the armor. HEAT rounds penetrate about 150% to 250% of their width. A 4 inch diameter HEAT warhead could penetrate between six inches to 10 inches of armor. If it is done wrong, the warhead makes a lot of noise and does nothing. To design and make the shape charge properly requires engineering experience that a terrorist simply does not have.

However, the terrorist does not need to struggle and make his own RPG. He can buy one. According to the United Nations Office on Drugs and Crime, terrorists can buy professionally manufactured RPGs, "The RPG-7 was issued by forces of the former USSR, the Chinese military and North Korea, and was used in many countries receiving weapons and training from the Warsaw Pact members. The RPG-7 is being used extensively by terrorist organizations in the Middle East and Latin America and is thought to be in the inventory of many insurgent groups. The RPG-7 is available in illegal international arms markets, particularly in Eastern Europe and the Middle East." Why would a terrorist try to make his own RPG and fail, when he can buy as many professionally made RPGs as he wants?

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Finally, there is the question of using amateur and high power rocketry components against heavily armored tanks. RPGs can be of some use against tanks even with reactive armor. From Wikipedia, The Free encyclopedia, "In Afghanistan, Mujahideen insurgents used RPG-7s to destroy invading vehicles. Multiple shooters were also effective against heavy tanks with reactive armor. The first shot would be against the driver's viewing prisms. After that, shots would be in pairs, one to set-off the reactive armor, and the second to penetrate the tank." However, as we just learned, it would be hopeless for the terrorist to make an RPG. What about a homemade rocket with a high density warhead that just penetrates the armor?

This type of high kinetic energy warhead works much like an arrow. It does not use an explosive and penetrates the armor based on its density and speed. The warhead would use a narrow metal rod (penetrator) with a pointed nose on one end. For this type of warhead to work it would have to be made of a very dense metal such as depleted uranium, tungsten or tungsten carbide. The terrorist will probably not be able to obtain depleted uranium, but he could buy the tungsten or tungsten carbide. Suppose he does buy one of those materials, now has a second problem. He needs very expensive and sophisticated metal working equipment to machine the high density metals into a penetrator. How likely is it that a terrorist is going to construct a high technology and expensive machine shop to produce anti-tank penetrators?

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Let's say that the terrorists somehow manages to get the penetrators made. Then, he has to make a rocket to deliver the weapon. According to Jane's Defence News, typical penetrators travel at a speed between 2,237 mph (3,280 fps) and 4,025 mph (5,904 fps). Suppose the terrorist designs for the average of the two speeds or 3,136 mph (4,600 fps). He has to make sure the penetrator is up to speed before it hits the ground, so it must be accelerated within one second from launch, which yields an acceleration of 4,600 ft/sec2 or about 143 g's. With this acceleration, the penetrator will be at armor penetrating speed within 767 yards from the launch point. If the rocket penetrator was fired horizontally, it would hit the ground approximately 854 yards from the launch point. The terrorist's homemade anti-tank weapon will only be good between 767 yards and 854 yards from the launch point. A target "kill" window of 87 yards starting about 0.44 miles away.

The first thing that is obvious from these numbers is that the rocket is not going to be made out of plastic, fiberglass or balsa wood. A rocket made out of these materials would disintegrate under 143 g's of acceleration and burn up when traveling over 3,100 mph. The rocket needs to be made out of a high strength metal to contain the "sledge hammer" rocket motor and high aerodynamic stresses. The terrorist is again going to need a quality machine shop. Second, the terrorist is going to have to aim this weapon at a tank that is 0.44 miles away. As before, he has the problem of knowing what the precise range is from his launch point to the tank. However, let's assume that he figures out the range and the tank is nice enough to stay parked so he can get off his shot. From the M1 tank schematic shown, its height is only about 8 ft. It is a very low profile target. The terrorist must aim his homemade rocket to within 0.1 degrees to hit a 4 ft radius around the center of the tank. Firing this type of "sledge hammer" rocket from a mobile launcher to within 0.1 degrees is not possible. The terrorist is going to miss the tank.

It is time for the Department of Justice and ATFE to confess that they have lied to the media, the Congress and the American people. They have made a ridiculous and false claim that amateur or high power rockets could hit armored vehicles up to five miles away. The best anti-tank weapons the US military can produce have a range of only 3.1 miles! Analysis shows that the Department of Justice and ATFE claims are absolutely false. Amateur and high power rocketry components would not enable a terrorist to construct any kind of weapon at any range that would destroy a light or heavily armored vehicle.

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