Editing Fusion drive

{{Era|UNSC|HCW|Post}}
[[File:ENGINES.png|thumb|300px|The fusion engines of a {{Class|Paris|heavy frigate}} at various levels of thrust.]]
The '''fusion drive''',<ref>'''Halo: The Fall of Reach''', ''page 16''</ref> also known as a '''fusion engine''',<ref name="maw">'''Halo: Combat Evolved''', campaign level ''[[The Maw]]''</ref><ref>'''[[Halo: The Flood]]''', Chapter 1, ''page 33'' (2003 paperback); ''page 36'' (2010 paperback)</ref> is a type of spacecraft [[Maneuver drive|maneuver drive]]<ref>'''Halo: Warfleet''', ''page 14''</ref> which serves as the primary form of sublight propulsion on most [[human]] spacecraft, whereas the [[Shaw-Fujikawa Translight Engine]] is used for travel at superluminal, or faster-than-light, speeds. The fusion drive system generates both power and direct thrust for the ship.<ref name="hwf">'''Halo: Warfleet''', page 33</ref>

==Description==
[[File:Autumn Arrival.png|thumb|250px|Rear view of {{UNSCShip|Pillar of Autumn}}, showing the thrust nozzles of its fusion engines.]]
The primary component of a fusion drive is an [[Wikipedia: Inertial electrostatic confinement| inertial electrostatic]] [[fusion reactor]] or a series of such reactors. The reactors on UNSC warships fuse [[Deuterium]] and [[Helium|Helium-3]] atoms{{Ref/Reuse|hwf}} to generate a stable and abundant supply of superheated [[plasma]] within a magnetic containment field.{{Ref/Reuse|maw}} The plasma is channeled into a series of exhaust manifolds, which vector it out of the ship's engine nozzles along with added water or hydrogen reaction mass to provide propulsion for the ship.{{Ref/Reuse|hwf}} The drive system utilizes inertial-electrostatic containment and higher-order manifolds to mitigate fusion backblast,<ref>[https://www.halowaypoint.com/en-us/forums/db05ce78845f4120b062c50816008e5d/topics/reality-of-halo-plasma/401b13b9-f097-45f3-a0a3-227d8f7d130a/posts '''Halo Waypoint:''' ''Reality of Halo: Plasma'']</ref> while magnetic fields and thrust-vectoring plates are used to improve maneuverability.{{Ref/Reuse|hwf}}

The main components of the fusion drive are typically located in a ship's [[engineering]].{{Ref/Reuse|maw}} The number of fusion engines varies between ship classes. [[UNSC frigate]]s are typically equipped with two primary reactors<ref>'''Halo 2''', campaign level ''[[Delta Halo]]'' (''"Both engine cores have spun to zero."'')</ref> and at least another two secondary reactors,<ref name="fs275">'''Halo: First Strike''', ''page 275''</ref> while {{Class|Halcyon|light cruiser}}s are powered by an array of three fusion reactors.<ref>[http://halo.xbox.com/Content/assets/en-us/ONI/577839090903298928/DDR-A340024-1115-08-27-52.pdf '''Halo Waypoint''': ''Data Drop 5'']</ref> Larger ships, such as the mobile hospital {{UNSCShip|Hopeful}}, could possess as many as six reactors.<ref>'''Halo: Ghosts of Onyx''', ''page 97''</ref> 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.

Fusion engines are capable of producing remarkable acceleration; using gravity-assist maneuvers to an advantage, human ships—from small [[diplomatic shuttle]]s to ''Halcyon''-class cruisers—are capable of crossing interplanetary distances in less than an hour.<ref>'''Halo: The Fall of Reach''', ''pages 324-329''</ref><ref>'''Halo: The Fall of Reach''', ''page 17''</ref>

For small-scale maneuvering, human ships utilize smaller chemical rocket thrusters placed around the vessel. Such thrusters expel chemical propellants such as [[triamino hydrazine]].<ref>'''[[Halo: Contact Harvest]]''', ''page 25''</ref>
{{Clear}}

==Development history==
Significant developments were made in fusion engine technology over the course of the 26th century; the Mark II Hanley-Messer fusion engines used by ''Halcyon''-class cruisers produced only a tenth of the power output of modern reactors as of [[2552]].<ref name="tfor238">'''Halo: The Fall of Reach''', ''page 238''</ref>

In 2552, the {{UNSCShip|Pillar of Autumn}} was refit with a power plant which 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.<ref>'''Halo: The Fall of Reach''', ''page 274''</ref>

==Known models==
===Mark II Hanley-Messer DFR===
The Mark II Hanley-Messer DFR is a type of deuterium fusion power plant used on {{Class|Halcyon|light cruiser}}s, which are typically equipped with three of the reactors.<ref name= "data drop">[http://halo.xbox.com/Content/assets/en-us/ONI/577839090903298928/DDR-A340024-1115-08-27-52.pdf '''Halo Waypoint''': ''Data Drop 5'']</ref> These fusion drives are designed for bulk maneuvering rather than speed.<ref>'''[[Halo Mythos]]''', ''page 94''</ref> They were obsolete by [[2552]], providing only a tenth of the power generated by modern reactors at the time.{{Ref/Reuse|tfor238}}

===Naoto Technologies: V4/L-DFR===
Manufactured by [[Naoto Technologies]],<ref name="evg228">'''[[Halo 4: The Essential Visual Guide]]''', ''pages 228-229''</ref> the V4/L-DFR is a deuterium fusion drive equipped on {{Class|Charon|light frigate}}s, such as {{UNSCShip|Forward Unto Dawn}}.<ref name="bulletin101012">[http://blogs.halowaypoint.com/Headlines/post/2012/10/10/The-Halo-Bulletin-101012-.aspx '''Waypoint''': ''The Halo Bulletin: 10.10.12'']</ref>

===XR2 Boglin Fields: S81/X-DFR===
Manufactured by [[Boglin Fields]],{{Ref/Reuse|evg228}} the S81/X-DFR is an advanced type of fusion drive serving as the primary sublight engine of the experimental warship {{UNSCShip|Infinity}}.{{Ref/Reuse|bulletin101012}}<ref>[[:File:Infinity fud scale.jpg|UNSC ''Infinity'' schematic]]</ref> Unlike most deuterium fusion drives of human design, the S81/X-DFR is classified as a form of [[repulsor engine]].<ref>'''Halo Mythos''', ''page 132''</ref> Massive in size, this engine module took fifteen years to design, build, and test.<ref>'''[[Halo: Warfleet]]''', ''page 42''</ref>

===Boglin Fields Starfire-IV fusion rockets===
Manufactured by Boglin Fields, two Starfire-IV fusion rockets were installed on the {{UNSCShip|Pillar of Autumn}} as part of the ship's refit for [[Operation: RED FLAG]] in [[2552]].<ref>'''Halo: Warfleet''', ''page 25''</ref>
<gallery>
File:HW Starfire-IV fusion drive.png|A Starfire-IV fusion rocket installed to the UNSC ''Pillar of Autumn''.
</gallery>

===OKB Karman 56K fusion drives===
Manufactured by [[OKB Karman]], two 56K fusion drives were used by the {{UNSCShip|In Amber Clad}}.<ref>'''Halo: Warfleet''', ''page 37''</ref>
<gallery>
File:HW 56K fusion drive.png|One 56K fusion drive in the ''UNSC'' In Amber Clad.
File:H2A - In Amber Clad Engine render.jpg|A render of one of ''In Amber Clad''{{'}}s fusion drives.
</gallery>

===Orphios Energy Systems Jupiter-1===
Manufactured by [[Orphios Energy Systems]], six Jupiter-1 maneuver drives were used by the {{UNSCShip|Spirit of Fire}}. These were salvaged from the destroyer {{UNSCShip|Calcutta}} and put in the ''Spirit'' in [[2530]].<ref>'''Halo: Warfleet''', ''page 49''</ref>
<gallery>
File:HW Jupiter-1 maneuver drive.png|Three Jupiter-1 maneuver drives.
</gallery>

===TANITH TKOFZ-2 Fusion Rockets===
Four TKOFZ-2 fusion rockets were used by the {{Class|Able|heavy destroyer}}s.{{Ref/Site|Id=CFDigsite|URL=https://www.halowaypoint.com/news/canon-fodder-digsite-dissection|Site=Halo Waypoint|Page=Canon Fodder - Digsite Dissection|D=28|M=07|Y=2023}}

==Use as improvised weapons==
[[File:POA-Destruction.jpg|thumb|The ''Pillar of Autumn's'' reactors detonating.]]
Fusion drives can also be used as improvised weapons of mass destruction. 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 reactor vents have been retracted. Significant amount of damage to the engines will trigger a "wildcat destabilization". The reactor will then detonate within minutes, generating a temperature of nearly 100,000,000 degrees. The most notable instance of this was when [[John-117]] destroyed [[Installation 04]] by overloading the fusion reactors of the {{UNSCShip|Pillar of Autumn}}.{{Ref/Reuse|maw}} The explosion was later revealed to be similar to a [[supernova]] to the point that it created a new element on [[Alpha Shard|a surviving shard]] of the ring.<ref>'''[[Halo: Nightfall]]'''</ref>

== Trivia ==
* There are inconsistencies in the potency of the UNSC's fusion drives between a few visual scenes and other sources:
** ''The Fall of Reach'' states quite clearly that a UNSC destroyer with its engines at 66% power is incapable of accelerating out of Sigma Octanus IV's ~0.5 g gravity well, and that fighting near a gravity well in general is considered crippling for UNSC vessels.<ref>''[[Halo: The Fall of Reach]]'', chapter 21.</ref> ''First Strike'' also states that a UNSC frigate's reactors, and thus the drives they power, have power output in the gigawatt range, consistent with fairly low accelerations.<ref>''[[Halo: First Strike]]'', page 285.</ref> Several other scenes in the novels allude to this being the case, such as when the UNSC ''Iroquois'' accelerates at full speed for at least several seconds and still ends up below the [https://en.wikipedia.org/wiki/Hypervelocity hypervelocity] floor (about 3 km/s), given the lack of explosive vaporization of the hull when it collides with a small Covenant ship.<ref>''[[Halo: The Fall of Reach]]'', chapter 21.</ref> Additionally, most visual depictions of space battles, such as the opening of ''[[Halo 2]]'', ''[[Halo Legends|The Package]]'', and ''[[Halo: The Fall of Reach - The Animated Series]]'' depict UNSC ships as either static or slowly drifting in combat, rather than being able to casually clear their lengths in a few seconds in order to dodge projectiles that consistently take at least that long to reach them. These are all consistent with the repeated mentions that the UNSC's reactors utilize [[deuterium]] fusion. 
** However, when the 478-meter UNSC ''[[UNSC In Amber Clad|In Amber Clad]]'' pursues the ''[[Solemn Penance]]'', it's shown to clear its own length in less than a second starting from a velocity of zero, putting its acceleration at over 100 g.<ref>'''Halo 2''', campaign level ''[[Metropolis]]''</ref> Despite using a fusion torch for propulsion, the ship also notably does not display any back-blast, which would be extremely hazardous to the city of [[New Mombasa]] below.
** [[Kenneth Peters]] commented on the inconsistencies during a behind-the-scenes video for the development of ''[[Halo: Warfleet – An Illustrated Guide to the Spacecraft of Halo|Halo: Warfleet]]''. He noted that, given that UNSC ships don't burn up the atmospheres of planets when engaged in them, their accelerations could not possibly be stupendously high. He also talked about the unintended consequence of unpublished figures giving UNSC ships sustained accelerations of 30 g, namely that such speeds would allow them to be used for "vaporizing planets" if they simply accelerated for an appreciable time in the direction of one. He went on to say that for these reasons, 343i decided not to give official acceleration figures for warships.<Ref>[https://www.youtube.com/watch?v=aE_O_it1Q5k&t=63m08s An Inside Look at Halo: Warfleet – A Guide to the Spacecraft of Halo] (starts 63 minutes and 8 seconds).</ref>

==List of appearances==
*''[[Halo: The Fall of Reach]]'' {{1st}}
*''[[Halo: Combat Evolved]]''
*''[[Halo: The Flood]]''
*''[[Halo: First Strike]]''
*''[[Halo 2]]''
*''[[Halo: Ghosts of Onyx]]''
*''[[Halo 3]]''
*''[[Halo: Contact Harvest]]''
*''[[Halo: The Cole Protocol]]''
*''[[Halo Wars Genesis]]''
*''[[Halo Wars]]''
*''[[Halo: Helljumper]]''
*''[[Halo 3: ODST]]''
*''[[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: Blood Line]]''
*''[[Halo: Reach]]''
*''[[Halo: Fall of Reach]]''
*''[[Halo: Glasslands]]''
*''[[Halo: Combat Evolved Anniversary]]''
**''[[Terminal (Halo: Combat Evolved Anniversary)|Terminals]]''
*''[[Halo: The Thursday War]]''
*''[[The Commissioning]]''
*''[[Halo 4: Forward Unto Dawn]]''
*''[[Halo 4]]''
**''[[Spartan Ops]]''
*''[[Halo: Escalation]]''
*''[[Halo 2: Anniversary]]''
**''[[Terminal (Halo 2: Anniversary)|Terminals]]''
*''[[Hunt the Truth]]''
**''[[All Hail]]''
**''[[The Cost]]''
*''[[Halo: Fleet Battles]]''
*''[[Halo 5: Guardians]]''
*''[[Halo: The Fall of Reach - The Animated Series]]''
*''[[Halo Wars 2]]''

==Sources==
{{Ref/Sources}}

[[Category:Propulsion]]