January 26, 2010:
The U.S. Army wants to use more precision "smart" weapons. To that end they have replaced unguided MLRS (227mm) rockets with a GPS guided one. There is now a very popular GPS guided 155mm artillery shell in use. Laser guided Hellfire missiles are widely used by helicopter gunships. But there's still one unguided "dumb" weapon that the army just can't seem to get away from; their unguided 70mm (2.75 inch) rockets. Back in 2003, the army planned to begin phasing out these rockets. But, instead, during the last five years, the army has purchased nearly a billion dollars worth of 70mm rockets. Not because they wanted to, but because the politicians from Vermont, where the rocket is manufactured, had enough clout to force the army buy over 100,000 70mm rockets they don't want, won't use, and will eventually have to dispose of. That last step will cost more money, unless they can find some foreign country that wants to buy them, cheap.
Meanwhile, there is a 70mm rocket that is worth buying. These are 70mm rockets that have been turned into laser guided missiles. These can be fired from a standard 70mm unguided rocket launcher. Two years ago, one of the American missiles, DAGR was declared ready for service, but the U.S. Department of Defense didn't respond with any orders. The big advantage of 70mm missiles is that they are one fourth the weight of a Hellfire, and one fourth the cost. That means AH-64s burn less fuel carrying them, and these smaller rockets are just as effective as a Hellfire in destroying many of the small targets found on the battlefield.
These missiles are basically a 25 pound 70mm rocket, with a laser seeker, a six pound warhead and a range of about six kilometers. Laser designators on a helicopter, or with troops on the ground, are pointed at the target, and the laser seeker in the front of the missile homes on the reflected laser light. The guided 70mm rocker weighs about 30 pounds (the 70mm rocket plus the guidance package).
The 2.75 inch (70mm) rockets were developed during World War II as an air-to-air weapon for use against heavy bomber formations. The Germans had developed a similar, and very successful weapon (the R4M), but before long it was noted that neither the Japanese nor the Germans had any heavy bombers, so the U.S. 70mm rocket was switched to air-to-ground use. Actually, the 70mm rocket was retained for air-to-air use into the 1950s, but it was never successful in that role.
The 70mm rocket became very popular in the 1960s, when it was discovered that the weapon worked very well when launched from multiple (7 or 19 tube) launchers mounted on helicopters. The 42-55 inch (107-140cm) long rockets could be fired singly or in salvoes, and gave helicopter pilots some airborne artillery for supporting troops on the ground. There are many variations in terms of warheads and rocket motors. Some versions can go over 10 kilometers.
Developing a guided 70mm rocket took so long because the manufacturers underestimated the technical difficulties of getting the laser seeker and flight control mechanisms into that small a package, at a weight and price the military could afford. The price of these missiles is about $20,000 each (about a third less than a smart bomb, and much less than a Hellfire missile).
The guided 70mm rocker is to be used against targets that don't require a larger (hundred pound), and more expensive Hellfire missile, but still need some targeting precision. These missiles make an excellent weapon for UAVs, especially since you can carry four of them in place of one Hellfire. The launcher for these missiles is built to replace the one for Hellfire, but carry four missiles.
But the U.S. Army is not interested in buying anymore 70mm missiles, no matter how accurate they are. Meanwhile, the guided 70mm rockets are being tested on U.S. Marine Corps AV-8 , and U.S. Air Force A-10 jets.