Directory of U.S. Military Rockets and Missiles
Appendix 4: Undesignated Vehicles
M712 Copperhead
Copyright © 2024 Andreas Parsch

Martin Marietta Copperhead (155 mm Projectile M712)

The concept of a guided artillery projectile was originally defined by engineers at the U.S. Army Rodman Laboratories in 1970. After successful feasibility studies in 1971, and a design competition between Martin Marietta and Texas Instruments in 1972, Martin Marietta was awarded a development contract for the 155 mm Projectile, M712 Copperhead, also referred to as CLGP (Cannon-Launched Guided Projectile). By the end of the 1970s, Copperhead was in full-rate production, and when that ended at some time in the 1990s, more than 20000 rounds had been delivered to the U.S. Army and U.S. Marine Corps.

Photo: White Sands Missile Range Museum

The M712 had a semi-active laser seeker for terminal guidance on the target, which had to be illuminated by forward troops or from helicopters. The projectile could be fired from a variety of 155 mm howitzers, incl. the M109, M198 and M777. After being fired, it followed a conventional ballistic trajectory. When the cloud cover was high or non-existing, the ballistic trajectory was followed until about 3 km from the target. Then the fins and wings were extended, and the seeker started to search for the laser-designated target. When a lock-on had been achived, the guidance system corrected for any aiming errors, for a high-precision hit on the target. In low cloud cover, ballistic flight mode was ended earlier at a predetermined point, the projectile extended its flying surfaces, and followed a lower glide path to the target. The guidance logic in this mode tried to steer the Copperhead to the target at the highest possible angle permitted by cloud cover and visibility. The M712 was equipped with an anti-armor warhead, and had an effective firing range of 3-16 km (1.9-10 miles).

Copperhead was used operationally by the U.S. Army during Operation Desert Storm in 1990/91, and Operation Iraqi Freedom in 2003.


Note: Data given by several sources show slight variations. Figures given below may therefore be inaccurate!

Data for M712:

Length137 cm (54 in)
Wingspan51 cm (20 in)
Diameter155 mm (6.1 in)
Weight62.4 kg (137.6 lb)
Range16 km (10 miles)
Warhead6.69 kg (14.75 lb) Composition-B anti-armor

Main Sources

[1] Bill Gunston: "The Illustrated Encyclopedia of Rockets and Missiles", Salamander Books Ltd, 1979
[2] Wikipedia: M712 Copperhead

Back to Directory of U.S. Military Rockets and Missiles, Appendix 4

Last Updated: 27 January 2024