V - 150 Planet Defender / Legends The v - 150 Planet Defender was a surface - to - orbit ion cannon produced by Kuat Drive Yards . Description . Manufactured by Kuat Drive Yards , the v - 150 Planet Defender was a massive , independently powered , surface - based ion cannon designed to target and neutralize starships in orbit of a planet . The v - 150 was usually mounted on a rotating base , and the weapon itself was covered by a semi - spherical shell of reinforced permacite . The weapon was designed to be modular , with an installation time of only a few hours . Each weapon was sold with its own reactor , which was intended to be buried forty meters below the weapon emplacement . Three levels of crew quarters and storage space were located between the reactor and the weapon , and the emplacement could store enough supplies to last the crew of twenty - seven for three months . When activated , it took several minutes for the v - 150 to maneuver into position on its rotating base . The v - 150 was completely immobile , and was vulnerable to attack from ground forces and aerial bombardment . A retractable blast shield protected the weapon , and the cover had to be retracted to fire the weapon . The v - 150 took targeting data from electrotelescope s and long - range sensors , and could also be linked to orbital sensor stations for more accurate targeting . The weapon had an optimum range of 4 , 000 kilometers , and a maximum range of 180 , 000 kilometers . The v - 150 ' s fire - control computers allowed the v - 150 to target orbital ships at will , and a single ion bolt could disrupt " Imperial " - class Star Destroyers . The weapon had a fire rate of one shot every six seconds . The v - 150 was commonly employed in conjunction with planetary shields ; as planetary shields were expensive to maintain , planets only powered them up when they were needed . Even then , the shields could take several minutes to reach full power . It was during these minutes that the v - 150 was vital to planetary defense , targeting enemy vessels in orbit before the shield could reach full power . The v - 150 was expensive , costing between 500 , 000 and 1 . 5 million credits , which was a quarter of the price of a full planetary shield . Planetary ion cannons were synchronized with planetary shields to allow the weapon to fire through the shields by lowering them for a split second . Even with the rotational base , each ion cannon had a limited fire vector of a few hundred square kilometers , so they were placed to protect vital bases , shield generators , spaceports and cities . History . The v - 150 Planet Defender was first proposed by a Gathi working for CoMar Combat Systems named Can Lar . CoMar rejected his proposal , stating that the design was " militarily useless and an engineering impossibility . " In response , Lar quit CoMar and attempted to find an employer that would take his design seriously . He found it in Kuat Drive Yards . Many Imperial planets bought v - 150s to supplement their defense setup and to reduce the cost of keeping their planetary shields active . The planetary ion cannons used by the Alliance were stolen during a hijack of a super transport in the Kuat system . The ion cannons were assigned to Echo Base on Hoth , and Bulwark . The others were at highly classified locations . Alliance crews referred to the weapon as the " 150 , " and it was the single most powerful weapon in the Alliance ' s ground - based arsenal . However , despite the expense and usefulness of the weapon , it was considered a disposable weapon to use in desperate circumstances , and abandoned during the evacuation . On Hoth , the crew manning the ion cannon were soldiers from Alderaan who were willing and eager to die at their posts to aid the Rebellion and hurt the Empire . Targeting data for the v - 150 on Hoth was supplemented by Echo Base ' s electrotelescopes and long - range sensors . Its power generator was remotely connected to the base ' s main reactors , which were scavenged from a " Praetor " - class Star Battlecruiser . While v - 150s were usually powered by reactors located forty meters below ground , the Echo Base generator was buried a full kilometer below the icy surface . Before its abandonment , the cannon provided valuable cover fire for the escaping transports of Echo Base as they attempted to run the blockading line of Death Squadron ' s " Imperial " - class Star Destroyers orbiting Hoth . From the base ' s command center , head controller Toryn Farr directed the ion cannon to fire upon the " Imperial I " - class Star Destroyer " Tyrant " , disabling it as the GR - 75 medium transport " Quantum Storm " , the first transport to evacuate Hoth , slipped past the Imperial warship and entered hyperspace . The Alderaanian crew stayed at the posts until the end of the battle , then set the v - 150 to explode to cover the last transports . However , the cannon itself was structurally intact and operational when Jaden Korr arrived in 14 ABY searching for the Disciples of Ragnos . Two v - 150 cannons were also present during Kyle Katarn ' s mission to Artus Prime . The New Republic used v - 150s to defend poor but strategically important worlds . They proved almost useless against the Yuuzhan Vong ' s biotechnology . Behind the scenes . The v - 150 Planet Defender first appeared with the release of and its tie - ins . The ion cannon at Echo Base subsequently appeared in many sources . One source states that the ion cannon was destroyed to cover the Rebels ' escape , although two other sources contradict that . In " " , a 2001 video game , the player is assigned to destroy the ion cannon and must do so before proceeding to the next objective . In " " , a 2003 video game , the ion cannon at Hoth is intact . This article incorporates information from all three sources . The ion cannon appears in the background of the Hoth map skirmish mission in the video game " " . It fires throughout the match .