The Death Star’s vulnerability was retconned for the Star Wars canon continuity in Rogue One: A Star Wars Story, and while the film excellently tied into the franchise’s 1977 debut, the battle station’s retcon was unnecessary. Rogue One created an all-new cast of characters, each of whom joined the Rebel Alliance and participated in the climactic Battle of Scarif for different reasons. In the case of Jyn Erso, one of her motivations was to finish her father’s work of sabotaging the Empire’s ultimate weapon, the Death Star, despite A New Hope succinctly explaining its weakness.
The Death Star, infamously, had a small thermal exhaust port that led directly to its main reactor. Rebel fighters exploited this weakness in A New Hope, with Luke Skywalker guiding a pair of proton torpedoes through the port and into the reactor, destroying the station. For years, viewers have questioned the logic behind a small and seemingly easily-exploitable weakness being the downfall of a moon-sized mobile space station that can destroy an entire planet, which likely motivated Rogue One’s retcon.
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Jyn Erso’s father, Galen Erso, helped design the Death Star’s superweapon, but secretly sabotaged the station by making the main reactor unstable. Erso paved the way for the Rebellion’s victory in A New Hope by designing the reactor to cause a catastrophic chain reaction if subjected to any pressurized explosion. The problem with this retcon is that reactors have always had catastrophic results when damaged or destroyed in the Star Wars franchise, so while Rogue One told an exciting story with compelling characters, it didn’t need to alter the Death Star’s weakness.
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