May 16, 2012:
Laser guided missiles for UAVs continue to get smaller. The latest one is the 5 kg (11 pound) Shadow Hawk. Based on the World War II five inch rocket (as was the original Sidewinder Air-to-Air missile), Shadow Hawk is 70mm in diameter and 68 cm (27 inches) long. Shadow Hawk is unpowered and can glide a kilometer or so to a target below. It was designed mainly for smaller UAVs (like the U.S. Army Shadow 200) that do not have the payload capacity for the 49 kg (108 pound) Hellfire. Shadow can only carry 45 kg of sensors or weapons. Thus a Shadow could carry a camera, a laser designator, and at least two Shadow Hawks.
There are several powered 70mm guided missiles already available. But these are heavier (13.6 kg/30 pound) and were developed for use against targets that don't require a larger and more expensive (over $100,000) Hellfire missile but still need some targeting precision. The 70mm missile (powered or unpowered) makes an excellent weapon for UAVs, especially since you can carry more of them. One type of launcher for these missiles is built to replace the one for Hellfire but carries four 70mm missiles instead of a single Hellfire.
All these 70mm rockets have a laser seeker, a 2.7 kg (six pound) warhead, and, for the powered ones, 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 70mm missile homes in on the reflected laser light.
Several other smaller missiles have been developed, and one of them, the Griffin, is being used in combat. The Griffin weighs only 16 kg (35 pounds) with a 5.9 kg (13 pound) warhead. Griffin has pop-out wings, allowing it to glide for long distances (up to 15 kilometers). UAVs can carry more Griffins, typically two of them in place of one Hellfire.