Fusion drive (Earth-5875)

A fusion drive, formally referred to as deuterium fusion reactor (DFR), is a spacecraft propulsion system that act as the primary sublight propulsion in all human spaceships, in conjunction with the Shaw-Fujikawa Translight Engine, which is used for superluminal and/or faster-than-light travel.

Alongside the fusion drive, human vessels used small rocket thrusters which employ triamino hydrazine as a propellant for maneuvering.

Description
An inertial electrostatic fusion reactor serve as the primary component of a fusion drive. It generates plasma, which is channeled into several exhaust manifolds across the ship that vector into the engine nozzles of the vessel. The exhaust of the drive serve as reaction mass to provide the propulsion for the ship. It include an exotic mechanism which employ high-order manifolds that eliminate the fusion backblast in the voyage. The deuterium fusion reactor, as implied by its name, is powered by nuclear fusion between deuterium isotopes.

The primary components of the drive are located in the engineering section of the ship. The number and model of drives vary between ship classes; UNSC frigates and destroyers are equipped with two primary reactors and two secondary reactors, while cruisers are generally equipped with three, large reactors. Larger vessels, such as the UNSC Hopeful, the UNSC Auriga, and the UNSC Infinity all have six drives. The engine exhausts' numbers also vary, although most ships have four or six primary adjacent nozzles.

Fusion drives are capable of heavy acceleration, and with gravity maneuverings, every human ship, from small commercial and tourism freighters, diplomatic shuttles, to large cruisers, can cross interplanetary distances in three hours.

Development history
Developments in fusion drive technology were made during the course of the 22nd to the 26th century.

In 2552, the Halcyon-class light cruiser UNSC Pillar of Autumn was refitted with a power plant that featured experimental architecture with only one main fusion drive within the reactor rings. Once activated, the secondary reactors would supercharge the main reactor, prompting to overlapping magnetic fields to boost the output by three hundred-percent, temporarily. This engine did not require external coolant systems like all reactors, and neutralized any waste heat.