The Normandy SR-2 was built by the pro-human black ops group Cerberus, using many technologies and design philosophies from the Systems Alliance frigate SSV Normandy SR-1. It was completed in the year 2185. The leader of Cerberus, the Illusive Man, gave command of the ship to Commander Shepard to help carry out his mission to go through the Omega-4 mass relay and attack the base of the Collectors.
Shepard went on many missions with the Normandy, including one where he recovered an identify-friend-foe system from a derelict Reaper, which would allow the ship to safely pass through the Omega-4 relay. The installation of the IFF took time, so Shepard used a shuttle to go on a mission. While Shepard was gone, the IFF introduced a virus to the Normandy's computers, shutting down most systems and transmitting a signal to the Collectors, who quickly attacked and boarded the Normandy. Most of the crew was abducted, but the pilot, Jeff "Joker" Moreau, managed to unblock the ship's AI, EDI, and reactivate the ship's power plant. EDI then vented the whole ship to space, killing all the Collectors onboard. When Shepard and his team returned, they found an almost empty ship.
Shortly afterward, Shepard took the Normandy SR-2 through the Omega-4 relay, where the Normandy was attacked by Oculus fighter drones and a Collector cruiser. The Normandy defeated them, but was severely damaged and crashed on the Collector base. While Shepard and his team assaulted the base, EDI restored power to the Normandy, and Joker piloted the ship away with the survivors of the mission.
Shepard and Cerberus parted ways after the raid on the Collector base, and Shepard was later arrested for destroying a mass relay (and the batarian colony in the same system) to keep the Reapers from using it to enter the galaxy. The Systems Alliance took control of the vessel during this period.
Months later, when the Reaper invasion arrived and attacked Earth, Shepard resumed command of the Normandy and left the planet to seek reinforcements.
The Normandy has several advanced stealth, computer, and tactical systems.
The Normandy's mass effect drive core is able to create mass concentrations in front of the ship, which the Normandy "falls" into, rather than using heat-producing thrusters. Combined with refrigeration of the ship's hull, the Normandy becomes virtually invisible to infrared sensors. The ship can only remain in stealth mode for a limited time (up to a few days, if heat generation is minimized) before the heat accumulated in the ship's heat sinks must be released.
An advanced AI called EDI (Enhanced Defense Intelligence) is installed aboard the Normandy. EDI operates the Normandy's electronic warfare and cyberwarfare suites. She is capable of hacking wireless networks and taking control of an enemy ship's computer system. In absence of a crew, EDI also can operate the whole ship, though she defers to Joker as a pilot due to the desirable unpredictability of human piloting.
The Normandy is armed with two unidentified projectile weapons- these may be mass accelerator cannons, or disruptor torpedo launchers. The Thanix Magnetic-Hydrodynamic cannon can be installed, upgrading its firepower to match that of a cruiser.
On the defense side, the Normandy has GARDIAN defense lasers for use against missiles and fighters, ceramic ablative armor to protect against energy weapons, and kinetic barriers to deflect projectiles from mass accelerators. The armor can be upgraded to Silaris armor, composed of carbon nanotube sheets woven with diamond via Chemical Vapor Deposition; these are crushed by mass effect fields into super-dense layers able to withstand extreme temperatures. The process also compensates for diamond's brittleness. The ship's kinetic barriers can be upgraded with Cyclonic Barrier Technology to substantially improve their performance.