Fusion drive

The fusion drive, also known as a fusion engine, is a type of spacecraft propulsion system which serves as the primary form of sublight propulsion on human spacecraft.

Description
The primary component of a fusion drive is a fusion reactor or a series of reactors. The plasma generated by the reactors is channeled into a series of exhaust manifolds, which vector it into the ship's engine nozzles. The drive exhaust serves as reaction mass, providing propulsion for the ship. The main components of the fusion drive are typically located in a ship's engineering.

The number of fusion engines varies between ship classes. UNSC frigates are typically equipped with two primary reactors and at least another two secondary reactors, while s are powered by an array of four fusion reactors. Larger ships, such as the mobile hospital, could possess as many as six reactors. The number of engine exhausts also varies greatly; ships usually have two or more primary adjacent exhaust nozzles, and a series of smaller, secondary ones. UNSC starship reactors are known to use deuterium, a light hydrogen isotope, as fuel. It is unknown whether the deuterium is fused with itself, or another hydrogen isotope such as tritium.

Development history
Significant developments were made in fusion engine technology over the course of the 26th century; the Mark II fusion engines used by Halcyon-class cruisers produced only a tenth of the power output of modern reactors as of 2552. The Pillar of Autumn's refit power plant used an experimental architecture where a single main reactor was nestled within two smaller reactor rings. When activated, the secondary reactors supercharged the main reactor, and their overlapping magnetic fields could temporarily boost the reactor output by 300 percent. In addition, the engine did not require external coolant systems like most reactors, instead neutralizing waste heat by means of a laser-induced optical slurry of ions chilled to near-absolute zero. The more power the reactor was generating, the more supercooled particles it produced, effectively cooling itself.

Other uses
Fusion drives can also be used as improvised weapons. A ship's captain possesses the codes necessary to initiate fusion core overload in their command neural interface, but reactor destabilization can also be initiated manually. Though the fusion reactors are protected by magnetic containment fields which surround the fusion cells, they can be destabilized by explosive ordnance once the exhaust couplings protecting the reactors have been retracted. Significant amount of damage to the engines will result in a "wildcat destabilization", a state which will cause reactor detonation within minutes. The most notable instance of this was when John-117 destroyed Installation 04 by overloading the fusion reactors of the.

List of appearances

 * Halo: Combat Evolved
 * Halo 2
 * Halo 3
 * Halo: Reach
 * Halo: The Fall of Reach
 * Halo: The Flood
 * Halo: First Strike
 * Halo: Ghosts of Onyx
 * Halo: Contact Harvest
 * Halo: The Cole Protocol
 * Halo: Evolutions - Essential Tales of the Halo Universe
 * Midnight in the Heart of Midlothian
 * Dirt
 * The Mona Lisa
 * The Impossible Life and the Possible Death of Preston J. Cole
 * Halo: Helljumper
 * Halo: Blood Line
 * Halo: Fall of Reach