How did wire-guided antitank missiles such as TOW guide their flight?

Wire-guided antitank missiles, such as the TOW (tube-launched, optically tracked, wire-guided) missile, utilize a command guidance system to direct their flight toward a target.12

In early iterations of this technology, the missile was tracked visually by a flare located on its tail, and the gunner manually generated guidance commands using a joystick to keep the flare superimposed on the target. The commands were transmitted to the missile through extremely thin wires that unspooled from the rear of the weapon as it traveled.12

Later, more sophisticated systems like the TOW automated this process. Instead of manual joystick control, the gunner simply keeps the target centered in an optical sight. The system then automatically tracks the missile and computes the necessary guidance commands, which are transmitted via the wire link to adjust the missile's flight path. While these early systems relied on physical wires, later developments in the 1980s began replacing them with optical fibres to transmit guidance data.12