At 62.4 kg and 140 cm long, Copperhead is longer and heavier than traditional 155mm ammunition.
For Copperhead to function, the target must be illuminated with a laser designator. Once the laser signal is detected, the on-board guidance system will operate the steering vanes to manoeuvre the projectile to the target. The Copperhead targeting logic is designed to (1) ensure that the optical system will always be able to detect the target, and (2) that once the target has been detected there will be sufficient time and velocity to manoeuvre to hit the target. Copperhead must be below any cloud cover at critical parts of the trajectory, and there must be sufficient visibility to ensure that when the target is acquired the projectile will have sufficient time to manoeuvre.(https://en.wikipedia.org/wiki/M712_Copperhead)