The
M712 Copperhead is a 155mm
artillery round used by the
U.S. Army. It has a
laser seeker and steerable fins for
terminal guidance, and is intended for use against
armored vehicles. The forward forces would
laser designate the target vehicles and call for a Copperhead
fire mission; the shell or shells would then home on the laser designated targets, steering themselves to
impact.
The Copperhead is not in general use. It was designed to improve the ability of NATO forces in Central Europe to respond to a massive Soviet tank incursion, by giving forward observers and other light forces the ability to kill armored vehicles. However, the round ended up being quite expensive as well as fairly fragile due to the early electronics used in its construction.
Today, the mission of the Copperhead has been taken over by more advanced weapons that don't require the constant presence of friendly forces, such as the JDAM and JSOW.