Talk About A Think Tank

The nuclear threat posed by the old Soviet Union may be gone. But as the Persian Gulf war demonstrated, it's impossible to keep advanced technology away from a determined despot. That's why the the Army Research Laboratory in Bethesda, Md., has launched the next phase of a never ending cat-and-mouse game involving tanks and antitank weapons.

The Army wants to develop tanks with "smart skins," which would be embedded with sensors that could analyze an incoming projectile and respond. It would all happen in the split second after the projectile hits, but before it penetrates a tank's armor. For example, a shell of ultraheavy depleted uranium that uses kinetic energy to plow through armor plate might trigger a repulsive explosion--the method already used by the latest reactive armor. A missile that burns through with a superhot plasma might be repulsed by a variety of different methods. The Defense Dept.'s Advanced Research Projects Agency is evaluating schemes proposed last month by several defense contractors.