Editing Nuclear weapon

{{Era|Human|UNSC|HCW|Post}}
{{Wikipedia}}
[[File:Atomicblast.jpg|thumb|250px|An atomic blast.]]
A '''nuclear weapon''' is a type of ordnance using [[nuclear fission]] and/or [[Nuclear fusion|fusion]] as a source of energy. The yield of a nuclear weapon is measured in the amount of tons of "[[wikipedia:Trinitrotoluene|TNT]]" needed to generate an explosion of similar proportions.

==Overview==
Nuclear weapons are commonplace in the [[United Nations Space Command]]'s arsenal and in select [[civilian]] uses. The UNSC uses nuclear weapons to great effect in [[space warfare]], increasing their effectiveness with special payloads enhanced for vacuum use.<ref>'''Halo: Ghosts of Onyx''', "Chapter 35" ''page 326''</ref> Throughout the [[Insurrection]] and early on in the [[Human-Covenant War]], space-borne UNSC nuclear weapons used proximity-fused warheads that relied on the detonation's direct radiation and thermal shock, which quickly proved ineffective against [[Covenant]] warships' [[energy shielding]]. As a result, the UNSC developed new types of warheads sporting [[Wikipedia:Nuclear pumped laser|nuclear-pumped]] X-ray lasers<ref name="warfleet 16">''[[Halo: Warfleet]]'', p. 16</ref> and Casaba Howitzer-type shaped-charge warheads known as "Spears", which focus the nuclear blast into a directed, relativistic plasma jet.<ref>''Halo: Warfleet'', p. 92</ref> Conventional nuclear weapons are still used in [[planetary warfare]] as tools of last resort.<ref name="warfleet 16"/> Some planetary nuclear weapons also have shaped-charge properties, such as the [[HAVOK tactical nuclear weapon#Mark 2550 MFDD|Mark 2550 Havok MFDD]], a bunker buster warhead designed to direct its blast against underground targets.<ref>'''Halo: Last Light''', ''page 364'' (Google Play edition)</ref>

Commonly, the casings of UNSC nuclear weapons such as the [[FENRIS nuclear warhead]]s are heavily reinforced, both to contain [[radiation]] and to boost the thermonuclear yield for containing the detonation for a split second longer.<ref>'''Halo: Ghosts of Onyx''', "Chapter 1", ''page 39''</ref> The hardened cases also protect the nukes inside and prevent them from going off accidentally - it was noted that detonating a bomb next to a FENRIS warhead would barely scratch the casing.<ref>'''Halo: Ghosts of Onyx''', "Chapter 23", ''page 209''</ref> There are various grades for the types of nuclear weapons. An example is the excavation-grade [[HAVOK tactical nuclear weapon]]. While presumably not as powerful as a military-grade weapon, a single warhead is described as being powerful enough to turn [[Ivanoff Station]] "into piñata" and was powerful enough to destroy ''[[Mantle's Approach]]'' and the [[Composer]] when detonated on the inside of the ship.

Nuclear weapons are also sold commercially, and are commonly used in [[asteroid]] mining. In [[2513]], an Insurrectionist suicide bomber used one such commercial explosive in a [[terrorism|terrorist]] attack on the [[Haven arcology]] on [[Mamore]], killing two million and injuring over eight million more.<ref>'''[[Intersystem News]]''': ''HAVEN TERROR BOMBING KILLS TWO MILLION''</ref>

An operational idiosyncrasy of nuclear weapons is the result of containing fissile material. Fissile materials, such as [[plutonium]], emit a readily detectable [[Čerenkov radiation]] signature upon exiting [[slipspace]] that negates stealth measures. As a result, if complete stealth is required, [[UNSC prowler|prowlers]] are forced to jettison any on-board nuclear weapons before transitioning back to normal space to avoid detection.<ref name="goo187">'''Halo: Ghosts of Onyx''', "Chapter 22", ''page 187''</ref> In addition, nukes launched from slipspace can easily be detected by enemy sensors, despite the use of [[Stealth ablative coating|stealth coatings]] or [[lead]] linings.<ref>'''Halo: Ghosts of Onyx''', "Prologue", ''page 15''</ref>

The [[energy shielding]] used in [[Covenant]] warships has been noted to dampen the [[electromagnetic pulse]] generated by the detonation of a nuke inside the ship. The [[SPARTAN-II program|SPARTAN-IIs]] used this to their advantage when they destroyed a [[Covenant cruiser at Longhorn Valley|Covenant cruiser]] during the [[Fall of Reach]], without risking damaging the nearby [[orbital defense generator]]s.<ref>'''Halo: First Strike''', "Chapter 3", ''page 25''</ref>

==History==
The first space-borne nuclear weapons were used during the [[Interplanetary War]] in the 22nd century.<ref>'''Halo 4: The Essential Visual Guide''', ''page 74''</ref> However, they were not considered a viable weapon of space warfare for the next several hundred years; at the time of the start of the [[Insurrection]] in [[2494]] it was widely believed that fissile detonations in space were practically useless, as the vacuum of space severely reduces the explosive yield and the resulting [[electromagnetic pulse]]. As such, it came as a surprise to the UNSC when the [[Insurrectionist]]s used a nuclear device in a space battle following the [[Callisto Incident|''Callisto'' Incident]], having hidden it in an [[asteroid]] in advance. When detonated, the nuke shattered the asteroid to molten pieces, which in turn destroyed one UNSC ship and severely damaged two more.<ref>'''Halo: Evolutions - Essential Tales of the Halo Universe''', "The Impossible Life and the Possible Death of Preston J. Cole", ''page 445''</ref> The Jiralhanae used nuclear weapons during their [[First Immolation|global civil war]] to such a degree that it set their species back hundreds of years.<ref>'''[[Halo: Envoy]]''', ''page 42''</ref>

Engagements against the [[Covenant]] during the [[Human-Covenant War]] quickly proved conventional nuclear weapons' ineffectiveness against Covenant warships' shields, forcing the UNSC to develop more effective payloads.<ref name="warfleet 16"/> The frequent deployment of nuclear weapons in space engagements constantly kept the UNSC's nuclear stockpiles near depletion. This occasionally forced them to resort to using obsolete nukes or [[Operation: UPPER CUT|unorthodox solutions]].<ref name="goo34">'''Halo: Ghosts of Onyx''', "Chapter 1", ''page 34''</ref><ref name="goo205">'''Halo: Ghosts of Onyx''', "Chapter 23", ''page 205''</ref><ref>'''Halo: Reach''', campaign level ''[[Long Night of Solace]]''</ref>

The Covenant did not generally use nuclear weapons, regarding them as "heretic" weapons. An exception to this were the [[Jiralhanae]], who had no qualms about using captured UNSC nukes or any other UNSC matériel.<ref>'''Halo: Ghosts of Onyx''', "Chapter 23", ''page 207''</ref><ref>'''[[Halo 2]]''', campaign level ''[[Uprising]]''</ref> However, following the end of the war, [[Covenant remnants|remnant groups]] of the Covenant have adopted more liberal policies in regards to human weaponry for practical reasons. Human-made nuclear weapons have subsequently fallen into the hands of Covenant [[terrorism|terrorists]] and cultists.<ref>'''Spartan Ops''', ''[[Departure]]''</ref>

==UNSC nuclear ordnance==
[[File:Nagasakibomb.jpg|thumb|The nuclear mushroom cloud seen in the bombing of Nagasaki in World War II.]]

The UNSC employs a range of nuclear ordnance.

===FENRIS nuclear warhead===
{{Main|FENRIS nuclear warhead}}
The '''FENRIS''' is a type of low-yield thermonuclear device. They were slated for decommissioning but munition expenditures during the [[Human-Covenant War]] saw the survivors return to service.<ref name="goo34"/><ref name="goo205"/><ref>'''Halo: Ghosts of Onyx''', "Chapter 24", ''page 215''</ref>

===Fury tactical nuclear weapon===
{{Main|Fury tactical nuclear weapon}}
The '''Fury''', formally designated as the '''Medium Fusion Destructive Device''',<ref>'''[[Halo: Reach]]''': ''[[Deliver Hope]]''</ref> is a rugby ball-sized device with a yield slightly less than a megaton. It is the "closest thing the UNSC has to a nuclear grenade".<ref>'''[[Halo: First Strike]]''', "Chapter 1", ''page 20''</ref>

===HAVOK tactical nuclear weapon===
{{Main|HAVOK tactical nuclear weapon}}
'''HAVOK''' is a series of 30 megaton thermonuclear devices, which come in various configurations. Some were delivered by ground forces during the Human-Covenant War.<ref>'''Halo: The Fall of Reach''', ''page 200''</ref><ref>'''Halo: The Fall of Reach''', ''page 212''</ref><ref>'''Halo Wars: Genesis''', ''page 17''</ref> One was used to destroy the [[Composer]] and the ''[[Mantle's Approach]]'', stopping the [[Ur-Didact|Didact]]'s [[New Phoenix Incident|assault on Earth]]. Due to its many variants, it appears to be one of the most commonly used nuclear weapons.

===HORNET mine===
{{Main|HORNET mine}}
The '''HORNET''' is a 30 megaton space mine. The devices are designed to be more stealthy than an ordinary nuke and are carried aboard [[UNSC prowler]]s. Although like all nuclear weapons, they can be easily detected when exiting slipspace,<ref name="goo187"/> they can be rendered practically undetectable by cooling them to near-absolute zero temperatures, same as that of interstellar space, in their launch chambers.<ref>'''Halo: Ghosts of Onyx''', ''page 325''</ref>

===NOVA bomb===
{{Main|NOVA bomb}}
The '''NOVA''' is a strategic device, and undoubtedly humanity's most powerful weapon. It consists of 9 nuclear warheads encased in a lithium triteride shell, which is compressed during detonation, boosting the yield "a hundred-fold".<ref>'''[[Halo: First Strike]]''', ''page 180''</ref> A single NOVA has enough power to cause complete devastation on a [[Joyous Exultation|planetary]] scale, and can destroy orbiting [[Malhiem|moons]] and [[Combined Fleet of Righteous Purpose|naval fleets]].<ref>'''Halo: Ghosts of Onyx''', ''page 244''</ref>

===Shiva-class nuclear missile===
{{Main|Shiva-class nuclear missile}}
The '''Shiva''' is a type of starship ordnance.<ref>'''[[Halo: The Fall of Reach]]''', ''pages 147, 322-324''</ref><ref>'''Halo: The Cole Protocol''', ''page 82''</ref> They may also be carried by [[GA-TL1 Longsword]]s.<ref>'''[[Halo Encyclopedia|Halo Encyclopedia (2011)]]''', ''page 320''</ref>

===Rudra-class nuclear missile===
{{Main|Rudra-class nuclear missile}}
The ''Rudra'' is another type of starship ordnance. The {{UNSCShip|Port Stanley}} carried multiple enhanced yield Rudra nukes.<ref>'''[[Halo: The Thursday War]]''', ''page 320''</ref>

===Hyperion-class nuclear missile===
{{Main|M4093 Hyperion nuclear delivery system}}
The Hyperion is a class of nuclear weapons shown to be carried by the {{UNSCShip|Forward Unto Dawn}} that is capable of destroying a {{Class|CRS|light cruiser}} in one hit if its shields are down.

==List of appearances==
{{Col-begin}}
{{Col-2}}
*''[[Halo: The Fall of Reach]]'' {{1st}}
*''[[Halo: The Flood]]''
*''[[Halo: First Strike]]''
*''[[Halo 2]]''
*''[[Halo: Ghosts of Onyx]]''
*''[[Halo: Contact Harvest]]''
*''[[Halo 3: ODST]]'' {{Mo}}
*''[[Halo: Legends]]''
**''[[Origins]]''
*''[[Halo: Evolutions - Essential Tales of the Halo Universe]]''
**''[[The Mona Lisa]]''
**''[[The Impossible Life and the Possible Death of Preston J. Cole]]''
*''[[Remember Reach]]''
**''[[Deliver Hope]]''
{{Col-2}}
*''[[Halo: Reach]]'' {{Mo}}
*''[[Halo: Fall of Reach]]''
**''[[Halo: Fall of Reach - Covenant|Covenant]]''
*''[[Halo: Combat Evolved Anniversary]]''
**''[[Terminal/Halo: Combat Evolved Anniversary|Terminals]]''
*''[[Halo: The Thursday War]]''
*''[[Halo 4: Forward Unto Dawn]]''
*''[[Halo 4]]''
**''[[Spartan Ops]]''
*''[[Halo: Escalation]]''
*''[[Halo: Nightfall]]''
*''[[Halo: Fractures]]''
**''[[Into the Fire]]'' {{mo}}
*''[[Halo: Last Light]]''
*''[[Halo: Envoy]]''
*''[[Halo: Retribution]]''
*''[[Halo: Legacy of Onyx]]'' {{Mo}}
*''[[Halo: Silent Storm]]''
*''[[Halo: Renegades]]'' 
{{Col-end}}

==Sources==
{{Reflist|2}}

[[Category:Nuclear weapons| ]]
[[Category:Weapons]]