Question: Star Wars: The Roleplaying Game's game system was slightly modified and rereleased in 2004 as which generic science fiction role-playing game (RPG) based on the "D6 System"?

Context paragraphs:
D6 Space: D6 Space is a generic science fiction role-playing game (RPG) based on the "D6 System".  Although derived, in part, from material originally presented in "The Star Wars Roleplaying Game", "D6 Space" is published as a stand-alone rulebook (not dependent upon or requiring other D6 System or Star Wars rulebooks) and is supported by its own line of supplements.

Star Wars: The Roleplaying Game: Star Wars: The Roleplaying Game is a role-playing game set in the "Star Wars" universe, written and published by West End Games (WEG) between 1987 and 1999.  The game system was slightly modified and rereleased in 2004 as "D6 Space", which used a generic space opera setting.  An unrelated "Star Wars" RPG was published by Wizards of the Coast from 2000 to 2010.  Since 2012 the official "Star Wars" role-playing game is another unrelated game, published by Fantasy Flight Games.

Star Trek Roleplaying Game: The Star Trek Roleplaying Game is a role-playing game (RPG) set in the "Star Trek" universe using the "CODA System" rules and first published by Decipher, Inc. in 2002.  When Decipher acquired the rights to create the RPG, they also acquired most of the gaming studio from Last Unicorn Games.  However, the Decipher game system is dissimilar to .  Instead, the system is similar to Wizards of the Coast's "d20 System" but uses 2D6 to resolve actions.

D6 Adventure: D6 Adventure is a generic role-playing game system based on the D6 System.  "D6 Adventure" is published as a stand-alone rulebook (not dependent upon or requiring any other D6 System rulebooks) and is supported by its own line of supplements.

List of D6 System books: List of D6 System books is a listing of commercially released books from West End Games, its successors, and licensees for the D6 System role-playing game.  This does not include various free downloads, fan-made works or forthcoming releases.  Accessories such as card decks, screens and miniatures are also not listed.  All books are print editions unless noted as otherwise.

D6 System: The D6 System is a role-playing game system published by West End Games (WEG) and licensees.  While the system is primarily intended for pen-and-paper role-playing games, variations of the system have also been used in live action role-playing games and miniature battle games.  The system is named after the 6-sided die, which is used in every roll required by the system.

Space Opera (role-playing game): Space Opera is a science-fiction role-playing game created by Edward E. Simbalist, A. Mark Ratner, and Phil McGregor in 1980 for Fantasy Games Unlimited.  While the system is applicable to the whole genre of science fiction, "Space Opera" had a default setting intended to be used as generic science fiction role-playing game rules, the focus being on creating space opera themed adventures.

Star Wars Roleplaying Game (Wizards of the Coast): The Star Wars Roleplaying Game is a d20 System roleplaying game set in the "Star Wars" universe.  The game was written by Bill Slavicsek, Andy Collins and JD Wiker and published by Wizards of the Coast in late 2000 and revised in 2002.  In 2007, Wizards released the "Saga Edition" of the game, which made major changes in an effort to streamline the rules system.

D6 Fantasy: D6 Fantasy is a generic fantasy role-playing game (RPG) based on the D6 System.  D6 Fantasy is published as a stand-alone rulebook (not dependent upon or requiring any other D6 System rulebook) and is supported by its own line of supplements.

Star Wars Miniatures: Star Wars Miniatures is a 34mm scale collectible miniatures tabletop game based on the "Star Wars" fictional universe that was produced by Wizards of the Coast.  The game was originally released in September 2004 and continued production until May 2010.  "Star Wars Miniatures" players build point-based squads from one of ten different in-universe factions then conduct battles between those squads.  The game mechanics are a simplified version of the d20 roleplaying game system.  Multiple maps, scenarios, and set themes from different settings and time periods from within the Star Wars universe are available.

Supporting paragraphs: Star Wars: The Roleplaying Game D6 Space
Answer: D6 Space