During the Galactic Civil War, Merr-Sonn Munitions, Inc. produced the PLX-2, a mobile missile launcher. This weapon proved to be quite effective against a variety of targets, including repulsorcraft, vehicles, aircraft operating in the atmosphere, fortifications, and even other missiles. A single soldier could operate the PLX-2, as it was designed to be a lightweight, shoulder-fired system. The launcher's design included a chamber for one missile ready to fire, and a secondary missile held in reserve. It had the capability to launch two distinct kinds of missile projectiles: unguided rockets, sometimes called "dumb" rockets, and GAM guided missiles. While the "dumb" rockets were launched using a direct line of sight, the GAM guided missiles could be programmed to lock onto a specific target. The GAM guided missile offered two modes of target acquisition, selectable via a stud on the launcher. EPR mode enabled the missile to lock onto IR signatures like vehicle engine heat or missile trails. Gravity-Activated Mode, which gave the missile its name, used the missile's internal computer to memorize the target's shape, then pursue it by tracking gravity-wave anomalies emitted from the target's repulsorlift system until it was in range to lock on. A GAM missile in GAM mode could maintain target tracking for up to forty kilometers before exhausting its fuel supply, but it was susceptible to being confused by alternative targets or thrown off by evasive actions.
However, the PLX-2 was known for its fragility, and damage to its targeting system could result from improper handling or insufficient maintenance. Although a launcher with a compromised targeting system could still launch "dumb" rockets, firing a GAM missile would cause the launcher to automatically select a targeting mode, leaving the operator unaware of which mode was active.
To launch a rocket, the firing stud on the launcher required two presses; the first press activated the guidance system, and the second actually launched the missile. It was common for inexperienced soldiers to rush or panic during combat, pressing the stud only once, which resulted in the missile failing to launch and the soldier being left confused.
Merr-Sonn later introduced an improved version of this weapon, known as the PLX-2M portable missile launcher.
Originally, it began as a prototype for the Grand Army of the Republic as a replacement for the PLX-1 portable missile launcher, and was used by some Republic commandos.