AT-AT

The All Terrain Armored Transport (AT-AT), also called the Imperial Walker, was a major part of the Galactic Empire's army in the fictional Star Wars universe. They were assembled by Kuat Drive Yards, and evolved from the previous built AT-TE Walkers and A5 Juggernaut, made for the Clone Wars. According to Star Wars creator George Lucas, the AT-AT's were based on the tripod fighting machines from The War of the Worlds. He also took inspiration from elephants and loading cranes in West Oakland--hence the nickname "elephant walker."

AT-AT's are "walking" armored personnel carriers; large, four-footed machines resembling mechanical camels or. Some literature describes the AT-AT at 15.5 meters tall, but onscreen measuring places them closer to 25 or even 30 meters or possibly even taller than that, for the AT-AT seems much taller than 40 meters to the public. Their primary purpose was transportation of combat units across the battlefield. It could carry either 40 Imperial Stormtroopers and five speeder bikes or two AT-ST units (partially disassembled due to height issues). Snowtroopers under combat conditions could be deployed via rappeling cable, but the heavier ordnance could only exit upon the slow and comparatively awkward process of the AT-AT kneeling and extending its ramps.

The arsenal of the AT-AT was also devastating, as they possessed two chin-mounted heavy laser cannons to destroy slow, bulky targets and two temple-mounted medium blaster cannons which could engage lighter targets. However, the AT-AT lacked any rear or top mounted weapons, leaving it with significant blind spots (particularly anti-air defense), although it countered this with strong protection that would deflect such potential attacks. The armor plating was extremely resistant to weapons fire, and the sturdy legs could walk over &mdash; and thereby crush &mdash; people and equipment. The tall legs could be used to cross difficult terrain, such as rivers, mountains and even swamps with reasonable ease and great protection.

AT-AT's could be configured to operate in varied planetary environments, known as the dunewalker when configured for desert terrain, or the familiar snow-walker for icy planets such as Hoth. An aquatic version, known as the AT-AT swimmer, also existed; the legs were traded for repulsorlifts, allowing the transport to function as a hovercraft.

At the Battle of Hoth in Star Wars Episode V: The Empire Strikes Back, the Empire used walkers to land beyond the limits of the Rebel Alliance's shield. General Maximillian Veers commanded the ground forces and advanced on the shield generator. Faced with such forces, Luke Skywalker devised a strategy to disable the walkers: his team of snowspeeders would use their magnetic harpoons and tow cables to entangle the walkers' feet, causing them to trip and fall, exploiting their high centre of gravity. Wedge Antilles and his gunner Wes Janson managed to disable one walker this way. It was then finished off with a Snowspeeder blaster shot to its vulnerable area just behind the neck. Luke destroyed a second by using his lightsaber to open a small hatch under the machine and tossing in a thermal detonator. When the Imperial walkers were destroyed, the entire crew and troop complements were killed. In the Empire Strikes Back novelization, a third AT-AT was lost when it mortally damaged but did not destroy Hobbie's speeder; the Rebel pilot suicidally steered his doomed craft into the command pod of an AT-AT. Luke also mentions Dash Rendar destroying a walker during the battle in the book "Shadows of the Empire".

AT-AT's later patrolled the garrison base on the Forest Moon of Endor, although they apparently did not take part in the battle against the Ewoks and Rebels. Luke Skywalker, after his surrender on Endor, was transported in one of these AT-AT's to meet Darth Vader at a landing pad.

AT-AT pilots are specially trained soldiers from the Imperial Army. They wear a grey uniform with white accoutrement similar in design to the black flight suite of TIE pilots.

It may be possible that the AT-AT's at the Battle of Hoth had better armor than the normal AT-AT, as evidenced by the apparent surprise by the rebels that their blasters were useless against them. Another possibility was that the Rebels had little experience facing AT-AT's and most of their anti-vehicle artillery batteries at Hoth were outdated even against weaker vehicles. The canonical Star Wars Customizable Card Game, for example, grants substantially greater power and armor values to units under General Veers' command as well as unique names (Blizzard One, Blizzard Two, etc). However, many Star Wars-themed video games such as Star Wars: Battlefront and Star Wars: Shadows of the Empire allow the player to destroy walkers with blasters, albeit with great difficulty. That difficulty may be the key point, as, in the movie, the Rogues gave up on their blaster cannons very quickly and the ground forces seemingly failed to accomplish much before being defeated.

Estimates on foot and step size put the estimated speed of the walkers deployed on Hoth at 9 km/h (6 mph), much slower than their top speed of 60 km/h (37 mph). Reasons for this include that they may have been carrying extra armor and/or equipment, or there may have been insufficient information as to the extent of the rebel base, which was underground and may have collapsed if a running AT-AT were to cross it. Another reason may be the snowstorm two days before the battle had left a fresh layer of snow on the ground, forcing the walkers to maintain slower speeds to keep their balance; similar to the way a person wearing snowshoes has to walk awkwardly to keep their balance. An AT-AT is an odd sight moving at its top speed and can be seen moving this quickly in the computer game Star Wars: Empire at War.

When controlled by excellent and skillful pilots (such as the pilots in General Veer's walker), an AT-AT is nearly invincible, even when the tow cable method is used against it. The walker can show surprising flexibility with good pilots, and when combined with its great firepower, it is anything but defenseless against snowspeeders, even though the AT-AT lacks any rear or top mounted weapons for anti-air defense. This can be seen in Episode V when a snowspeeder comes head-on against General Veers' AT-AT. Without seeing any open shots, the speeder pilot veers to the right. Seeing this, the expert walker pilots perform a maneuver where it leans on and stretches its legs, and moves its head to the side. The walker's "cheek" cannons fired and destroyed the speeder, sending it spinning out of control, until it crashes in a fireball. The original version of the PC game Star Wars: Galactic Battlegrounds had snowspeeders immune to AT-AT fire, but the expansion pack later retracted this invulnerability.

AT-AT's in the Expanded Universe
The AT-AT mostly supplanted the older HAVw A5 Juggernaut as the choice for leading Imperial ground assaults.

The AT-AT, in the service of the Army of the Republic, first saw action in the Clone Wars during the Battle of Jabiimas the Clone Turbo Tank, although improvements to the AT-AT model were made over time, leading to a mission in the computer game Star Wars: Galactic Battlegrounds, in which Darth Vader and General Veers must release a prototype of a new type of AT-AT (the one shown in The Empire Strikes Back) to put down a Rebel uprising on Zaloriis.

Inside the Worlds of Star Wars Trilogy shows that AT-ATs and AT-STs were deployed from the Y-85 Titan Dropship.

Sometime after the Battle of Endor, the Empire's AT-AT's replaced their lasers and blasters with light turbolasers, easily capable of defeating many hardened defensive weapons emplacements, armor and structures.

Apparently, X-Wing lasers are much more powerful than the anti-vehicle artillery used in Echo Base, since in X-Wing: Isard's Revenge, Rogue Squadron takes advantage of the AT-AT's lack of anti-aircraft armament to wipe out four AT-AT's fairly rapidly using only their quad-linked laser cannons. When one of the Rogues quipped that the job would've been done much faster if they used their proton torpedoes, Wedge Antilles (Rogue One) replied that the proton torpedoes were saved for usage against any capital ships they might encounter on their exfiltration.

An alternative explanation for the difficulty the Rebel forces had in destroying the AT-AT's on Hoth is because the walkers employed heavy reflective armor due to the importance of the mission, and regular AT-AT deployments would be more susceptible to damage from blaster or laser cannons.

One story in the Expanded Unverse tells of a rookie AT-AT Pilot (Davin Felth) who had his vehicle kneel to avoid a harpoon attack during a training exercise. The Empire, embarrassed by the then unknown flaw, reassigned the rookie to a remote position where he could never tell of the discovery.

Models

 * LEGO has made four versions of the AT-AT. One is a miniature version, another is a larger one with over 1000 pieces retailing at about US$100, the third was a LEGO Mindstorms set, incorporating a motor allowing it to walk, and another taking the design of the last two with the ability to walk. This set is coming in later 2007.

Pop culture

 * In Command & Conquer: Tiberian Sun, GDI uses a tank of similar design, as a MKII of the series's trademark Mammoth Tank.
 * As part of a series of running Star Wars jokes in the cartoon network show Kids Next Door, vehicles resembling AT-AT's made from school buses appear in the episode Operation: S.N.O.W.I.N.G., right down to the commander and drivers wearing armor resembling their movie counterparts.
 * An AT-AT also appeared in a Star Wars parody in an episode of The Simpsons. It smashes down the wall of a crowded council meeting, then calmly sits and begins to read a newspaper.
 * A skit on the show Robot Chicken which later made the show's Top Ten Star Wars Moments mocks when Luke throws the bomb into the belly of one walker in episode V. In the skit when he throws the bomb in, a snowtrooper is seen sitting on the toilet right in front of the hole in the floor when the bomb is thrown in. He curiously asks, "What in the f*** is..." Before the bomb explodes destroying the walker and him.
 * Lee Seiler sued LucasFilms in the mid-1980s, claiming that the AT-AT infringed on his copyright on what he called a "Garthian Walker," which he said he created in 1976 or 1977. The case was dismissed with the court noting that not only did Seiler not produce the supposed drawings at trial, but that the copyright came one year after The Empire Strikes Back debuted, in 1981.