The Air Force recently tapped Triton Systems, out of Chelmsford, Mass, to develop such a "Modular Disc-Wing Urban Cruise Munition." "The 3-D maneuverability of the Frisbee-UAV [unammned aerial vehicle] will provide revolutionary tactical access and lethality against hostiles hiding in upper story locations and/or defiladed behind obstacles," the company promises.

The circular drones will be lanuched "from munitions dispensers or by means of a simple mechanism similar to a shotgun target (skeet) launcher," Triton adds. Once in the air, they'll be tele-operated by soldiers on the ground. Or, if needed, the fightin' frisbees will pilot themselves as they hunt for guerrillas.

Once they catch up to the baddies, the drones will use a series of armor-piercing explosives, shooting jets of molten metal, to eliminate their targets. And these MEFP [Multiple Explosively Formed Penetrator] "warheads will be controllable so as to provide a single large fragment (bunker-buster) or tailorable pattern of smaller fragments (unprotected infantry or light utility vehicles)." The decision of whether to go bunker-buster or infantry-annihilator mode can either be determined by the drones' human operators, "or autonomous target classification routine built into the UAV."

Now, Triton's Frisbee-UAV concept isn't the first time roboticists have looked into disc-shaped drones. From 1992 to 1998, the Navy experimented with a set of unmanned, 250-pound, six-foot-diameter flying saucers. In 2002, Norweigan researchers showed off plans for a circular flying robot "inspired at least partly by the design of Star Trek's USS Enterprise," New Scientist noted.

Around the same time, at the University of Manchester, Jonathan Potts studied how best to control UAVs "based on the Frisbee TM sports disc shape." "The Frisbee disc has proven its potential on the sports field as a platform for short free-flights," Potts wrote back in an '01 paper. Without "predefined flight orientation," a Frisbee drone "offers novel flight characteristics and manoeuvrability. It is potentially suitable for a variety of mission objectives fulfilling surveillance, communications, munitions and/or airborne radar warning systems."