Project Stardust, also known as the Death Star project, and the Ultimate Weapon project, was the project that saw the construction of the first Death Star superweapon. In 21 BBY, the Galactic Republic began secret construction on the Death Star on Geonosis, by order of Chancellor Palpatine. After the Clone Wars had ended and the Republic became the Galactic Empire, they moved the almost completed Death Star into open space to finish the final adjustments and begin operations.
Project Stardust was the codename for the Imperial effort to create the superweapon known as the Death Star. Although the project would not yield a completed weapon until the year 0 BBY, the original efforts began during the Clone Wars when the then Galactic Republic acquired designs for the battlestation from the Confederacy of Independent Systems.
Ultimately, Project Stardust saw the creation of a superweapon capable of destroying entire planets. Although the first Death Star would be destroyed by the Alliance to Restore the Republic during the Battle of Yavin, the Empire developed a second Death Star that would also be destroyed at the Battle of Endor.
The name "Project Stardust" was a result of a key scientist, Galen Walton Erso, who called his daughter Jyn "stardust." Erso would desert the project and the Empire completely so as to not see the weapon completed, but was eventually hunted down and forced to return to the project.
Count Dooku holds the plans for the ultimate weapon given to him by Poggle the Lesser.
During the First Battle of Geonosis, Sith Lord Darth Tyranus was given the Death Star plans by the Geonosian leader Poggle the Lesser, designed by his weaponsmiths. He then took the plans with him to Coruscant to give to his master, Darth Sidious, the corrupted chancellor of the Republic .
During the Clone Wars, Supreme Chancellor Palpatine set up the Death Star project secretly under the Galactic Republic, and only a handful of individuals knew about it. Members of both the Republic Special Weapons Group and the Strategic Advisory Cell were responsible for the project's advancement. Orson Krennic, a member of both organizations, was particularly determined to develop the weapon before the Republic's enemies could.
Jedi General Aayla Secura came close to discovering the plans when she infilitrated the Secret Research Facility on an unmapped moon. But she was stopped by Dark Acolyte Asajj Ventress who engaged Secura in a lightsaber duel and took back the plans.
Later during the Clone Wars, Sidious acquired a massive kyber crystal from the planet Utapau that he wanted to use in the Program. The crystal was, however, destroyed by the Jedi Obi-Wan Kenobi and Anakin Skywalker, which necessitated the world's occupation so the hunt for similar crystals could continue.
After the end of the Clone Wars, the fall of the Republic, the destruction of the Jedi Order, and the rise of the new Galactic Empire, now-Emperor Palpatine continued the project. Construction began on Geonosis, although after three months of work, Poggle and the Geonosians betrayed the Empire and began destroying what they had built. However, the Empire relentlessly continued to funnel resources into ensuring the Project's completion. Around 18 BBY, the research conducted under Project Necromancer by the Imperial cloning program was destroyed and its facility, Mount Tantiss, was ransacked while Chief Scientist Royce Hemlock and several troopers of the Advanced Science Division died during the attack. Believing that Hemlock’s failings costed the Empire enough, Tarkin ordered Captain Bragg to have Mount Tantiss shuttered indefinitely and redistribute all of his requested funding and assets to Project Stardust. By 5 BBY, a large portion of the station had been constructed.
Jyn Erso stole the datacard containing Project Stardust from the Imperial vault on Scarif.
During the Lothal campaign, Krennic persuaded the Imperial Security Bureau to divert the funding of Grand Admiral Thrawn’s TIE/d "Defender" Multi-Role Starfighter Program to his Project until it was complete after the Rescue of Hera Syndulla since the Imperial Armory Complex went out of business.
Shortly before the Battle of Yavin, the Rebel Alliance stole the Death Star plans, with the efforts of Rogue One. The plans were themselves codenamed Stardust, allowing Jyn, who was recently recruited by the Rebel Alliance, to recognize and transmit them to the Alliance Fleet before she died.
After the Battle of Scarif, the plans were sent to Princess Leia Organa aboard the Tantive IV. As the plans were sent across the galaxy, they ultimately made it to the moon Yavin 4, where the rebels disovered a weakness in the form of an exhaust port, leading her twin brother Lieutenant Luke Skywalker to bring an end to Project Stardust when he destroyed the Death Star and killed Governor Tarkin and serval other senior officers of Imperial High Command.
The First Order's Starkiller Base was inspired by and designed after the results of Project Stardust.
Project Stardust first appeared, albeit unidentified, in the 2002 film Star Wars: Episode II Attack of the Clones. The project was later identified in the one-shot issue Darth Vader Annual 2, written by Chuck Wendig and published by Marvel Comics in 2018.