Question: 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 which generic science fiction role-playing game (RPG), based on the "D6 System"?

full_context: Document 1: 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.
Document 2: 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.
Document 3: 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.
Document 4: Star Wars Customizable Card Game: Star Wars: Customizable Card Game (SW:CCG) is a customizable card game based on the "Star Wars" fictional universe. It was created by Decipher, Inc., which also produced the "Star Trek Customizable Card Game" and "The Lord of the Rings Trading Card Game". The game was produced from December 1995 until December 2001. Operation and oversight of the game was then taken over by a Decipher created volunteer group called the Star Wars Customizable Card Game Players Committee. To date, the Players Committee, or PC, still runs the game and creates new cards known as "virtual cards" that are released online in PDF format, and can then be printed and played with. "SW:CCG" can also be played online: Holotable.com is the official Player Committee platform.
Document 5: Star Wars Roleplaying Game (Fantasy Flight Games): The Star Wars Roleplaying Game is a tabletop role-playing game set in the "Star Wars" universe first published by Fantasy Flight Games in August 2012. It consists of three different standalone games, each one conceived to play a particular type of character:
Document 6: 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.
Document 7: Serenity Role Playing Game: Serenity Role Playing Game is a science fiction role-playing game released in 2005 and set in the universe of the movie "Serenity". It was produced by Margaret Weis Productions, Ltd, and its mechanics were the first iteration of the Cortex System. It won an Origins Award for best RPG in 2005 and Margaret Weis' license came to an end on January 31, 2011.
Document 8: 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.
Document 9: 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.
Document 10: Twilight Imperium: The Role-Playing Game: Twilight Imperium: The Role-Playing Game is a role-playing game published by Fantasy Flight Games in 1999.
Document 11: 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.
Document 12: 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.
Document 13: Cortex System: The Cortex System is a generic RPG system based on the "Sovereign Stone System ", and was developed by Margaret Weis Productions, Ltd for the Serenity Role Playing Game. It was subsequently used for their licensed "Battlestar Galactica" and Supernatural RPGs, and brought out as a stand-alone system in the "Cortex System Role Playing Game" book (also called the "Cortex Classic System Role Playing Game"). Serenity, using the Cortex System, was the 2005 Origins Award Gamer's Choice Role Playing Game of the Year.
Document 14: CORE Command: CORE Command is a science fiction role-playing game published by Dream Pod 9 since 2003. It introduces a far future space opera universe for role-playing, featuring advanced science, gigantic spacecraft and epic space battles.
Document 15: GURPS Space: GURPS Space is a "genre toolkit" for creating Science Fiction campaigns using the GURPS role-playing game. It performs a similar purpose as GURPS Fantasy does for Fantasy games. Rules and guidelines are provided for running games from science fantasy and space opera to hard science fiction, creating worlds and planets and notes about aliens races. The first edition was published in 1988.
ground_truth: D6 Space