M712 Copperhead

The M712 Copperhead is a 155 mm cannon-launched guided projectile, an artillery shell that steers itself onto a target lit by a laser designator. Engineers at the U.S. Army's Rodman Laboratories defined the concept in 1970, and after feasibility studies in 1971 and a design competition in 1972 between Martin Marietta and Texas Instruments, Martin Marietta won the development contract. Fired from standard 155 mm howitzers such as the M109, M198 and M777, the round follows a ballistic path and then extends its fins and wings to glide, homing on reflected laser light with a semi-active seeker. Its shaped charge warhead of about 6.7 kilograms of Composition B is meant for tanks and other hard point targets at ranges of 3 to 16 kilometres. It reached full-rate production by the end of the 1970s, was used in Operation Desert Storm, and more than 20,000 rounds were delivered to U.S. forces before production ended.