The Whirlwind Multiple Missile Launcher, also known as the Whirlwind Missile Launcher or simply Whirlwind Launcher, is the dorsal-mounted primary weapons system of both the Adeptus Astartes' Whirlwind artillery tank and the Land Raider Helios heavy tank. The Whirlwind Launcher is also capable of being used by the Deathstorm Drop Pod variant of the Astartes Drop Pod. This weapon system was also used by the Deimos Whirlwind during the Great Crusade and Horus Heresy era of the of the late 30th and early 31st Millennia. Housing cadaverous telemetric-Servitors, the Whirlwind Multiple Missile Launcher is a superlative fire suppression weapon. Inscribed with scrolling text invoking the Emperor's judgement, the Whirlwind Launcher's warheads are death to infantry and light vehicles alike.
The number of missiles carried by the Whirlwind varies by pattern. The Helios Pattern, which is the most common, carries six missiles in total, while the older Thalia Pattern carries a total of twelve smaller missiles. The Mark II Mars Pattern carries ten missiles, in two clusters of five each.
A Whirlwind Multiple Missile Launcher, like an Earthshaker Cannon, possesses a short minimum range that it is unable to fire within. However, this is offset by the long range of its missiles and their wide blast radius. A Whirlwind Multiple Missile Launcher will normally be armed with two different types of missiles to fire in artillery salvos, and are able to switch between these two during the course of battle. Vengeance Missiles are geared towards destroying light vehicles and medium-armoured infantry, whilst Incendiary Castellan Missiles are able to flush enemies out of cover with their fiery blasts.
The Whirlwind Missile Launcher is capable of firing multiple types of missiles, many of which are arcane and can only be found within the quantum-sealed stasis chambers of the Deathwatch and other secretive bodies within the upper echelons of the Imperial war machine. The following is a list of known types, including:
- Vengeance Missiles - Vengeance Missiles represent the standard high-explosive missile warhead used by the Adeptus Astartes.
- Castellan Missiles - Castellan Missiles are tipped with a special warhead that can be set to explode at specific times and altitudes to scatter small, mine-like bomblets across a designated target area. Castellan Missiles can establish makeshift mine fields quickly and without exposing Imperial forces to unnecessary dangers while laying mines.
- Incendiary Castellan Missiles - An Incendiary Castellan Missile's warhead has been further modified to scatter burning Promethium over a designated target area rather than bomblets. These horrific weapons are used to burn to death lightly-armoured enemy infantry and light vehicle formations.
- Hyperios Air-Defence Missiles - The Whirlwind is capable of firing Hyperios Anti-Air Missiles that are guided to strike enemy aircraft. The Whirlwind Hyperios uses similar missiles, although the anti-air weapons used by the Whirlwind Hyperios and Hunter Patterns of the Whirlwind are much more effective at the anti-aircraft role. Whirlwinds armed with Hyperios Anti-Air Missiles are rarely deployed on the battlefield, due to the existence of the aforementioned more effective alternatives.
- Frag Missile - Frag Missiles are designed to explode on impact with any surface, raking the immediate area with lethal shrapnel composed of aerodynamic metallic shards. Though Frag Missiles are primarily intended to be used as anti-infantry weapons, they can also be deployed effectively against light vehicles. Frag Missiles are often ineffective against heavily armoured infantry.
- Krak Missile - Krak Missiles are primarily intended to serve as anti-vehicle weapons, and contain a high-strength shaped charge with a relatively small blast radius, but they cause massive damage to anything they hit with minimal collateral damage. Krak Missiles are also very effective against heavily armoured infantry, bunkers and other armoured or fortified static targets where their concentrated explosives will often punch holes straight through armour. However, a Krak Missile's small blast radius makes them impractical for use against most infantry and moving targets.
- Plasma Missiles - A very rare type of missile used by the Whirlwind, Plasma Missiles are mentioned within various archives, but are hardly ever used in combat in the present day.
- Super-Krak Missiles - A very rare type of missile used by the Whirlwind, Super-Krak Missiles are mentioned within various archives, but are hardly ever used in combat in the present day.
- Vortex Missiles - An incredibly rare type of missile that used smaller versions of the Vortex Warhead.
- Special Missiles - A wide variety of uncommon missile types including those with gas, Anti-plant, Heywire, and Tanglefoot warheads.
- Codex: Space Marines (6th Edition), pg. 122
- Codex: Space Marines (5th Edition), pg. 79
- Imperial Armour Volume 2 - Space Marines & Forces of the Inquisition, pp. 143, 146-147, 149, 152-153, 253
- Imperial Armour Volume 2, Second Edition - War Machines of the Adeptus Astartes, pp. 25, 158, 161
- The Horus Heresy: Book One - Betrayal by Alan Bligh (Forge World Series), pg. 220
- Imperial Armour Volume 12, Fall of Orpheus, pp. 153
- Imperial Armour - Apocalypse, pg. 27
- Imperial Armour - Apocalypse II, pp. 28, 35