UK Contact: Claire Bowles

US Contact: New Scientist Washington Office

New Scientist

Cruise missiles are about to get a whole lot scarier. Existing flying bombs are told exactly where to go. But the US Air Force is now developing a cheap cruise missile that chooses its own targets.

Once launched, the cruise missile will patrol the skies and hunt down armoured vehicles, tanks, surface-to-air missile batteries and even Scud missiles. It will even be smart enough to take evasive action when attempts are made to shoot it down.

The idea, says Ken Edwards, project director at the Air Force Research Laboratory (AFRL) in Eglin, Florida, is to send the low-cost autonomous attack system (LOCAAS) missiles into areas where military intelligence has little information on targets. They will be dropped in bunches of four by aircraft (see Diagram). The missiles, which are powered by a small turbojet engine, will then head to the target area and initiate a search pattern. A major advantage of the technology is that this kind of mission would normally risk a fighter pilot’s life.

Another goal, says Edwards, is to keep the cost of a missile well under $100,000 — considerably less than the million-dollar price tag of a Tomahawk cruise missile. He says the savings come from having a single, self-sufficient system for navigation and tracking. In addition to a GPS satellite navigation system, the missiles use lidar — a laser-based radar system — to sense the lie of the land.

Besides gleaning navigational information from the laser reflections, the AFRL team have also devised a technique for identifying targets based on their reflected laser “fingerprint”. A LOCAAS missile will be able to identify a number of target types and prioritise them, says Edwards. So if it seeks a Scud and fails to find one, it will look for the next target category.

A unique feature of LOCAAS is an ability to adapt its warhead to suit the type of target: if it decides to destroy a missile launch pad, it first fragments a metal rod in its warhead to cause the most damage with multiple impacts. But if its target is a tank, it keeps the rod intact to lend it maximum density for penetrating armour.

There are bound to be fears about having such destructive weapons flying around with no one controlling them or choosing the targets. After all, in the Kosovo conflict, even NATO pilots were sometimes unable to distinguish between tanks and fleeing refugees. The designers will have to prove their automated targeting system is reliable and that the device can fail safely when it runs out of fuel.

Yet according to Tom Anderson, an expert in systems reliability at the University of Newcastle, engineering such a weapon shouldn’t be too difficult. He says it’s feasible that a system such as LOCAAS might actually prove safer than today’s weapons. “Humans are far from infallible,” he says, as was demonstrated last year during the Kosovo conflict when, according to the official version of events, CIA officers using out-of-date maps accidentally targeted the Chinese embassy in Belgrade.


Reporter: Duncan Graham-Rowe