Mark 2488 Onager

Template:Ratings Template:Weapon Infobox The 15cm Mark/2488 1.1GJ MAC, also known as the Onager and often referred to as a "mass driver", is a stationary Magnetic Accelerator Cannon used by the United Nations Space Command during the Human-Covenant War.^[1]

Design details

The Onager is capable of firing a 15 cm round with up to 1.1 gigajoules of kinetic energy.^[1] It has five linearly arranged magnetic coils, each of which needs to charge individually before each shot. The weapon needs to cool off after every shot, and does so by opening a radial vent on the upper portion of the barrel. The weapon is operated from a small booth on the left side of the cannon.^[2]

Operational history

During the Fall of Reach, a group of UNSC Marines installed an Onager on top of one of the planet's ship-breaking facilities in Aszod to protect the drydocked UNSC Pillar of Autumn. Emile-A239 manned the mass driver to fend off incoming Covenant Banshees and Phantoms before the Autumn could take off.^[2] However, the SPARTAN was killed by a Sangheili Zealot, prompting SPARTAN-B312 to commandeer the cannon and successfully delay the Covenant assault on the Autumn by crippling an incoming CCS-class Battlecruiser with a shot to its ventral energy projector.^[2]

Trivia

The Onager named after a medieval siege weapon, which in turn takes its name from a horse subspecies.
On the Bungie.net weapons statistics page, the description for the Onager is simply "I need a weapon", a reference to a line by John-117 in the opening cinematic of the level Cairo Station in Halo 2.
"S-239" is painted on the Onager's frame. This is a reference to Emile-A239, who is killed while operating the weapon.

Gallery

A first-person view of the Onager.
The Onager, manned by SPARTAN-B312, firing a round at the incoming Covenant CCS-class Battlecruiser.
An Onager's electromagnetic coils charging before it fires.
The control booth of an Onager cannon.