The endeavor known as Operation Skyhook served as the Rebel Alliance's designated strategy for securing the Death Star plans and, in the end, obliterating the Imperial war machine, the Death Star.
This Operation Skyhook evolved into one of the most devastating series of conflicts during the entire war. The superlaser weapon system of the Death Star would annihilate the entire population of Alderaan, a planet allied with the Alliance. During the Battle of Yavin, Rebel pilot Luke Skywalker fired a "lucky shot" that resulted in the destruction of the Death Star, eliminating hundreds of thousands of Imperial personnel, including Grand Moff Wilhuff Tarkin.
In the year 2 BBY, Mon Mothma, Bail Organa, and Garm Bel Iblis, the leading figures of the Rebel movement, were captured by Darth Vader, the Supreme Commander of the Imperial forces, and transported to the battle station. While imprisoned, they became aware of the existence of the Death Star, although they did not fully comprehend its true destructive power. Operation Skyhook was initiated shortly after their escape and the passing of their savior, Galen Marek.
Whispers regarding the construction of a massive Imperial weapon began when the Genue was rescued. Rebel survivors who had escaped from the secret prison facility known as Stars' End informed the Alliance that Wookiee slaves were being forced to work on a clandestine project. Simultaneously, R2-D2's investigations into Imperial computer networks revealed evidence of an "Imperial superweapon," rumors that were later substantiated through inquiries within the galactic underworld.
The Alliance mounted a rescue operation to free Wookiee slaves being transported on Toral. By examining the ship's manifest, the Alliance uncovered information about a weapons convoy located near Orron III. An assault on this convoy led to the acquisition of Imperial communications satellites, which subsequently transmitted the superweapon's schematics to the Rebel outpost AX-235. The Rebel spies stationed at AX-235 confirmed the existence of the Death Star.
Around the same time, Princess Leia Organa embarked on a humanitarian mission to deliver medical supplies to the Ralltiiri High Council. However, her primary objective was to provide the Ralltiiri resistance movement with heavy weaponry and military equipment to combat the Imperial occupation forces. Commodore Tion of the Imperial task force granted her permission to land. While on Ralltiir, Leia rescued a wounded Rebel soldier named Basso, who revealed the existence of the first Death Star. Back on Alderaan, Bail Organa informed his adopted daughter that Basso's account of a top-secret Imperial weapons project overseen by Wilhuff Tarkin had been verified. Later, Tion visited Alderaan and met with the Organas. Leia cleverly tricked him into revealing that the Death Star was a moon-sized battle station equipped with a superlaser capable of obliterating entire planets. Lord Tion inadvertently disclosed that an Imperial convoy was transporting the Death Star plans from Governor Tarkin's headquarters to the Imperial vaults. After Leia inadvertently revealed her knowledge of the Death Star, Tion realized that the Organas were connected to the Rebel Alliance, but he died before he could alert the Imperial authorities.
Acting upon the advice of Princess Leia—referred to operatives only as an anonymous "friend in the Senate"—the Alliance's Chief of State, Mon Mothma, ordered a more in-depth investigation into the nature of this weapon. Utilizing previously gathered data, the Rebels discovered that cargo shipments destined for a research station working on the Death Star were originating from the Vergesso Asteroids. Captain Raymus Antilles personally recruited the smuggler Han Solo, despite Solo's reservations, to plant a tracking device and EMP device within one of the cargo containers headed for the research station.
The tracking device revealed the station's location above Corulag, and the EMP device was triggered, paralyzing Imperial security forces. Antilles then led a team to attack the station, successfully recovering valuable data. The team was able to confirm the project's name—Death Star—and gain a general understanding of its destructive capabilities, but they lacked the detailed technical schematics needed to identify a weakness. Mon Mothma instructed Leia Organa to intensify intelligence-gathering operations and assigned Antilles to her service aboard the Tantive IV.
As the Death Star's location became more widely known, the Rebels proceeded with the Mission to Danuta. During this mission, Rebel operative Kyle Katarn, who had recently defected from the Galactic Empire, was tasked with retrieving the plans from a secret Imperial base located in the city of Trid. Due to their critical importance, these plans were physically transported to Princess Leia aboard the diplomatic vessel Tantive IV via the shuttle Maria. In addition to the fragments obtained from AX-234 and Danuta, it appears that another portion of the plans was delivered from a Rebel base on Polis Massa. These plans were stolen during a prisonbreak on the Death Star. Lord Vader's personal stormtrooper legion, the 501st Legion, attempted to recover this information on Polis Massa, but it was smuggled out. This event spared the 501st from the destruction of the Death Star. Additional information was retrieved on Darkknell by Senator Garm Bel Iblis, who was presumed dead at the time, shortly after the deaths of his family at the hands of Imperial agents.
The final piece of the plans was recovered by Rebels operating from Toprawa, but Imperial reinforcements led by Lord Vader blockaded the system. The information was intended to be delivered to the Star Cruiser Liberty, but the sudden appearance of the Star Destroyer Immortal forced the transfer to be aborted. Under the guise of a mercy mission, Princess Leia Organa arrived in the system aboard the Tantive IV, hoping that her diplomatic immunity as a member of the Imperial Senate would protect her. However, Lord Vader's flagship, the Devastator, detected the transfer, and Princess Leia was forced to flee the system with the Emperor's lieutenant in pursuit. There was a spy onboard which helped the Imperials track the vessel.
Tantive IV fled towards Tatooine in an attempt to accomplish its secondary mission: locating Obi-Wan Kenobi, a former Jedi General who had survived the Great Jedi Purge and was now in hiding on Tatooine. Princess Leia had been instructed by her father to seek him out if all other options were exhausted. Leia intended to bring Kenobi to Alderaan, along with the stolen plans. Regrettably, before the ship reached Tatooine, it was intercepted by Vader's flagship, the Devastator.
The Tantive IV was quickly disabled and captured. Although the Rebels on board put up a small struggle, the stormtroopers of the 501st Legion swiftly overwhelmed them and captured Princess Leia. However, the boarding party failed to locate the plans, which had been secretly uploaded into the astromech droid R2-D2, who then escaped in an escape pod.
While the Alliance searched for the Death Star's location, General Jan Dodonna suggested that destroying the base at Kalla VII would strand any ships heading towards the Death Star there. According to this plan, Red Squadron assisted in its destruction while Priam arrived and, as predicted, was stranded. After capturing Priam, its computer revealed to the Alliance that the Death Star was located at Despayre. The rebel carrier Fortressa then launched a disastrous solo attack on the Death Star at Despayre and was completely destroyed along with her starfighter compliment. Later, when Rebel scouts Ethar went to investigate, the Death Star had already left the system, and they were captured by lingering Imperial forces.
Following the Destruction of Alderaan, a tracking device was placed on the Millennium Falcon, which led the Imperials to the moon Yavin 4. To confirm Rebel presence on the moon, Emperor Palpatine ordered an expeditionary force to land and establish a stronghold. After a brief skirmish near the Massassi Arena, Rebel presence was confirmed.
With the Death Star approaching Yavin 4, General Dodonna formulated a complex plan to destroy the Death Star using only a pair of proton torpedoes. Red Squadron and Gold Squadron would fly into the Death Star's trench and fire into a secondary thermal exhaust port leading from the main exhaust port, causing the battle station to explode from within.
The Battle of Yavin commenced shortly thereafter. The Alliance emerged victorious when Luke Skywalker, flying as Red Five, successfully fired into the Death Star using the Force.
The threat posed by the Death Star was eliminated. However, the Empire later retaliated with other special projects, including the dark trooper production line, the development of TIE Phantoms and the Tarkin battlestation. Their efforts eventually led to the TIE Experimental Project and, ultimately, the construction of the Death Star II.
Although the X-Wing Collector's CD-ROM: The Official Strategy Guide states that Operation Skyhook began after the capture of the Tantive IV, later sources such as The Essential Atlas clarified that this is not possible. The second phase of Operation Skyhook results in the acquisition of the Death Star plans, which are then sent to the Tantive IV.