The bad guys can use drones too. While billions have been spent on ballistic missile defense, little attention has been given to the more imminent threat posed by unmanned air vehicles in the hands of terrorists or rogue states.Building a ballistic missile is a big deal. They take a lot of development it really is rocket science which is expensive and hard to keep secret. At best, youll end up with something like a Scud missile with a range of a few hundred miles and limited accuracy. You would not be able to aim at an individual building.Unmanned air vehicles are another matter. They are small, cheap and you could buy one tomorrow. Short-range versions with video cameras are common, but thanks to GPS and Google Earth you can also put one to within a few yards of your aim point from long range. Very long range in 2003 a TAM-5 UAV with a six-foot wingspan was flown over 1880 miles across the Atlantic Ocean. One scenario features a mass drone attack launched from a tanker or freighter well out in international waters.Eugene Miasnikov of the Center for Arms Control, Energy and Environmental Studies at MIPT, calls the UAV a suicide bomber on steroids, basically. Unlike a suicide bomber, a drone can easily penetrate security and threaten otherwise safe areas (eg the Green Zone) or reach crowded public places like spots stadiums. Dense crowds would lead to large numbers of casualties from fragmentation bombs, and an attack by multiple UAVs could cause panic and further injuries in the crowd. And don't even get us started about chemical, biological or dirty bomb radioactive payloads.Already, there have been a number of terrorists using (or, at least, intending on using) UAVs. Bin Laden had a plan to assassinate President Bush at the G8 summit, the FARC in Colombia bought drones. Hezbollah flew a "Mirsad-1" drone over Israeli territory in 2004.Another paper by Dennis M. Gormley, on UAVs and Cruise Missiles as Possible Terrorist Weapons draws similar conclusions about the ease with which such weapons can be used and the difficulty of intercepting small, slow aircraft. He notes a significant incident in Iraq:
Moreover, two Iraqi ultra-light aircraft managed to fly directly over the 3rd Infantry Divisions logistical encampment and disappeared before orders could be arranged to fire at them. Even the use of expensive airborne reconnaissance systems such as AWACS would not help. Their radars intentionally eliminate slow-flying targets on or near the ground to prevent their data processing and display systems from being overtaxed.One solution to the threat of hostile UAVs is DARPAs Peregrine. This is a drone-killing drone, designed with dual propulsion mode to combine long loiter time on patrol with a dash capability for intercept. Spending on Peregrine has gone up from nothing in 2004 to $1.4m in 05 and $5m in the coming year. In Popular Mechanics, Noah and friends tried designing one of the drone-fighters. The one here was provided by The Mad Planeman whose blog tinkers with aircraft design.But killing drones isn't the hard part, really. It's detecting and identifying before they can do damage that poses the biggest challenge. As Miasnikov points out if they are launched a few miles from their target there may be only minutes to react.Those with long memories or an interest in esoteric weapons will recall that we have been here before. During WWII the US came under attack from thousands of small, long-range unmanned aircraft Japanese Fugo balloon bombs. Thirty feet across and made of mulberry paper, each carried three incendiary bombs to the US mainland all the way from Japan. Although they were dismissed at the time, tremendous resources were put into countering them. And although they did little damage, the Fugos were originally intended to carry biological agents, which would have made them a far more serious threat.How great the threat is this time remains to be seen.-- David HamblingUPDATE 2:46 PM: There is no doubt that cheap and plentiful drones will be everywhere in future, used for everything from newsgathering to traffic control and fighting forest fires. The way will be led, as usual, by military...Theres a section on them in my book, Weapons Grade.UPDATE 05/02/06 8:56 AM: Just how cheap and easy are these UAVs to build? Well, as CF points out, the Society of Automotive Engineers holds a drone-making contest every year for students. The machines cost anywhere from $1,000 to $5,000 to build, he says. And the winning plane can generally haul between 30 and 40 pounds -- with just a 1.5 horsepower engine.