Deployed to the 16th Autonomous Mobile Squadron and assigned to the Pegasus-class warship, the Thoroughbred, the RX-78-4 Gundam G04 was designed to be able to use a prototype mega beam launcher with destructive power equivalent to that of a capital ship. In order to power such a weapon, the RX-78-4 was outfitted with a heavier power plant than its sister unit, the RX-78-5. Like the RX-78-5, the RX-78-4 can be outfitted with a booster system which extends the operational range and time of the mobile suit in space operations. The RX-78-4 only used the mega beam launcher once, in order to stop a reinforcing fleet from Granada. Though the launcher was successful in destroying the fleet, the load it put on the RX-78-4's power plant was too much for the unit to bear, and resulted in the RX-78-4 taking severe damage and killing its pilot. This version of events has always been in dispute. During the final battles of the One Year War there were unconfirmed accounts of the RX-78-4 showing up in battle. (In the comic version the artist created the story that Luce was killed and he insert the "IF" it happened story later, the story told us that Ford brought Luce out of Unit 4 before it explode, and after that Unit 4 (Repaired) and Unit 5 was in service till the end of the battle of A Bao A Qu.) First appear as part of Kunio Okawara's MS Collection original design series, design by Kunio Okawara. The design was updated to be use in Mobile Suit Gundam: Encounters In Space video games by Hajime Katoki.