this second version of the original Imperial battle station was modified to eliminate the flaws which were discovered by the Alliance military and exploited during the Battle of Yavin. Like its predecessor, the second Death Star was designed around a planet-smashed superlaser. The primary difference between the two battle stations was the elimination of dedicated thermal exhaust ports. In their place, millions of millimeter-wide vents were dispersed across its surface, each with a dedicated baffling mechanism. The second Death Star was slightly larger than the original, at 160 kilometers in diameter. Note that Inside the Worlds of the Star Wars Trilogy indicates that the second Death Star was over 900 kilometers in diameter. The outer hull was made from quadanium steel for protection. For defensive measures, the second Death Star was to house 4 capital ships, 7,200 TIE fighters, 3,600 Lambda-class assault shuttles, 2,480 blast boats, 1,860 drop ships, and 13,000 support craft. These included 1,400 AT-ATs, 1,400 AT-STs, 178 Mobile Command Bases, 1,420 repulsortanks, 1,420 repulsorcraft, 355 Floating Fortresses, and 4,843 Juggernauts. In addition to its primary superlaser, the second Death Star was also planned to have some 30,000 turbolasers. Another key difference between the two battles stations was their purpose. While the first Death Star was designed to instill fear in planetary systems, the second Death Star was designed as the bait in an elaborate trap. Emperor Palpatine, sensing that the end of the Galactic Civil War was at hand, began construction of the new battle station in orbit around the Forest Moon of Endor. Palpatine appointed Moff Jerjerrod as the overseer of the project, knowing that he was an ineffectual leader who would be unable to keep the station's construction on schedule. Then, he purposely allowed news of the battle station's construction to leak out. A group of Bothan spies was given access to the information, and pursuing Imperials forces were ordered to ensure their eventual escape. Palpatine hoped that the Alliance military would not pass up the chance to destroy the new station, in hopes of crushing the Empire. Palpatine even leaked schedule information that showed the exact times he would be visiting the station during its construction, as further incentive to incite an attack. In preparation, the Emperor massed a huge fleet just outside of the system, hidden until the Alliance fleet made its appearance. During the Battle of Endor, Alliance forces discovered that the second Death Star was fully operation, despite its incomplete structure, and was capable of targetting starships as well as planets. However, Palpatine failed to account for the love between Darth Vader and his son, Luke Skywalker. As the space battle raged, Vader managed to overcome his hatred and return to the Light Side of the Force, killing Palpatine in the process. With their leader dead, the Imperial forces were unable to continue the fight, and the second Death Star was eventually destroyed.