Fighter

Fighters are a broad category of aerial and space-based combat craft smaller than cutters. They are optimized for low-endurance, high-maneuverability missions, and never wander far from a carrier, space station or airbase. Over time, fighters have assumed various roles depending on the prevailing technological and doctrinal schema of aerospace warfare.

Fighters have historically been broadly divided into atmospheric fighters and space fighters (or exoatmospheric fighters), though the two categories have converged to a considerable degree with technological progress. By the mid-26th century, most craft dubbed space fighters are also capable of atmospheric incursions, or at least landing on a planet. In an atmosphere, fighter craft dominate the battlespace. In space, they are used to augment the capabilities of a larger ship or engage small targets, but do not have significant role in all-out fleet battles.

Aerospace fighters are used to extend a capital ship's power-projection capability from the vacuum into an atmosphere, or conversely, are able to carry out independent orbital missions from an atmosphere. Many of these are capable of surface bombing missions. Deep-space fighters are intended to perform incursions outside a planet's orbit, but rarely interplanetary distances. Such craft are typically larger and fitted for longer-duration missions than aerial fighter jets, and may also be known as strikecraft, gunboats or missile boats depending on their mission profile. Some are large enough to blur the line between fighter and cutter, with some craft historically classified as fast-attack craft falling into this boundary. Fighters capable of spaceflight are sometimes dubbed starfighters in the media and corporate contexts, though this term is rarely used in the actual military and is generally regarded as quaint.

Overview
The difference between fighter missions in an atmosphere and in space is greater than it may readily appear. Though superficially similar to atmospheric fighters, space fighters are technically more analogous to seaborne gunboats; unlike fighter jets launching from a maritime fighter-carrier, they occupy the same medium as the larger ships. Most spaceborne fighters are thus optimized for operational niches where "pure" spacecraft are at a disadvantage, especially a planet's atmosphere, allowing the larger ship to hang back in a higher orbit.

One of the core dilemmas of the space fighter is that of endurance versus maneuverability. The allure of the fighter is that their short-term missions allow more of the craft's precious mass to be allocated for engines, propellant, and weapons, whereas larger ships require far more extensive facilities for crew quarters, life support and provisions. A fighter can be operated by a small crew, even a single pilot, but they cannot wander far from the mothership or operate for extended periods of time; additionally, a fighter carelessly expending its delta-v budget on combat maneuvers may not be able to return to the carrier under its own power, creating additional difficulty and fuel cost for the carrier as it has to retrieve its stray fighter. This has become less of an issue with the development of compact fusion drives, which most fighter craft now have; prior space fighters were powered solely by chemical rockets, though some larger types had nuclear engines.

Another adversary to the development of true strike fighters or dogfighters are guided missiles. While the engagement distances between even other fighters could be measured in tens if not hundreds of kilometers, missiles meant that any potential opponent could wipe you out well before you could get into range with conventional guns. Although countermeasures do provide a reprieve, they don't usually matter until they are deployed seconds before impact, as most guidance systems (especially those coordinated by an AI or mothership) are very good at picking decoy to actual target. To get an elite fighter close enough to destroy an enemy ship without being annihilated at some point was not only madness, but suicidal.

Most of the problems associated with fighters have to do with the human inside; a trained pilot is simply too valuable to be wasted on suicide runs. The obvious solution to this was to do away with the human entirely and use drones, especially as UNSC automation improved. Drones may be expensive, but they are also far less so than human-piloted craft, are able to perform maneuvers that would liquefy a human, and require no life support. In addition, many of the direct actions involved in space combat are already performed by automated systems, the velocities and distances simply being too great for human reaction times to handle, even with the use of direct neural input controls on state-of-the-art fighters.

These realizations led to a schema in which UNSC space fighters grew progressively larger and came to encompass more functions and capabilities, almost making some of them small warships in their own right; however, this also meant carriers were able to carry fewer fighters, though carriers also increased in size to compensate. Meanwhile, dedicated air-breathing fighters or short-range aerospace fighters have remained consistently small and nimble. Though drones and guided missiles have taken up many of their former niches, the UNSC has continued to field manned fighters throughout its existence.

Unmanned fighters are used in roles considered too risky for human pilots, or ones requiring only simple instructions. Drones can endure faster accelerations than manned craft and are far more disposable, allowing precious mass and space to be taken up by propellant and weapons; such craft are usually little more than missile buses or glorified missiles themselves. Many models of manned fighter craft, such as the Longsword, can also be remotely operated on missions that require no human presence (or are regarded as too risky for human pilots). Manned fighters may also be used as command craft to direct drone squadrons. The UNSC is generally squeamish about fully autonomous war drones for historical reasons, so most of the drone fighters' critical functions are still remote-controlled either from a warship or a manned fighter, which has to stay close enough to the drone for light lag not to become a major issue. The Covenant's devastatingly effective point defenses (and subsequently high fighter pilot casualties) have recently prompted the UNSC to give their drones more autonomy, however.

Some super-maneuverable fighters use cockpits filled with specialized crash gel in which the pilot is immersed in order to mitigate the physiological effects of g-forces, allowing such craft to perform more extreme maneuvers and withstand sudden impacts. However, this comes with its own downsides, such as the complicated logistics of getting in and out of the gel-immersion cockpit and accompanying life-support equipment, particularly when in a rush. As such, this is limited to specialized strikecraft. The most modern fighters incorporate gravitic inertial compensators to achieve the same effect, though these are less reliable.

Space fighters and gunboats
Rather than engaging capital ships directly, space fighters are focused on engaging enemy dropships or minor spacecraft, as well as providing command-and-control for drone squadrons or missiles. Early space fighters were often non-aerodynamic, being fully optimized for vacuum operations, though these craft were usually referred to by nautical terms such as gunboat, missile boat or fast-attack craft. After propulsion technology improved to the point fusion drives could be used on fighters, most space fighters were given an atmospheric capability. Although space fighters tend to be capable of longer-duration missions than atmospheric fighter jets, their endurance is ultimately limited by onboard consumables and crew facilities. Most carry enough provisions to last several days, and large gunboats may even have onboard cryotubes. The ability to land on planets also allowed larger fighters such as the Longsword to act as a low-capacity insertion or exfiltration craft a limited degree. Even so, craft that truly blur the line between fighter and dropship remain few.

Space fighters are utilized in a variety of roles. Outside all-out war, they may be used by commercial ships in anti-piracy and escort roles and even orbital search and rescue. During wartime, fighters are commonly deployed against dropships and other parasite craft of larger ships, or enemy fighters. Fighter squadrons may also take on small warships such as cutters and corvettes, whose point defenses fighter swarms are able to still comfortably overwhelm. The theory for counter-fighter engagement is to bring as much payload to bear as you can, while minimizing the enemy's ability to target you via ECM or interference by other craft. Fighters also operate as support for a warship such as a frigate or cruiser in one-to-one combat scenarios. However, they can contribute little to large-scale fleet engagements outside peripheral roles.

Fighter combat in space has little to do with aerial combat and even less with the traditional pop culture image of dogfighting. Similar to combat between larger ships, relative velocities between opposing craft are usually measured in multiple kilometers per second. As most fighter battles occur near planetary bodies, orbital mechanics are a major consideration that firmly distinguishes space combat from the aerial kind. Missiles dominate at long ranges, and any close-range clashes are mostly brief flashes of action as combatants speed past one another. In some cases, however, spatial fighter combat may occur in the same or relatively close moving reference-frame (e.g. an orbit), resulting in more conventional "knife-fight" clashes between fighters; this became particularly common during the Human-Covenant War due to the Covenant's tendency to drop their fighters from a carrier in slipspace into close proximity to their target at a similar overall vector, partially or fully circumventing the UNSC's preferred long-range missile strikes.

The Covenant use space fighters in a more conventional manner than the UNSC because their anti-AI dogma bans most autonomous drones or automated targeting and firing systems, with the effectiveness of their missile guidance systems also being limited. In addition, Covenant plasma weapons are most effective at close ranges, especially on a fighter scale. The Sangheili have a long and proud history of dogfighting, which lent itself well to this paradigm. Consequently, the Covenant use fighters against a wider variety of targets than the UNSC, including direct attacks on capital ships. While such missions have high casualty rates against point defense, the Covenant's casual perspective toward death on the battlefield means they have fewer qualms about casualties. Even so, experienced pilots are not readily wasted, and cunning commanders generally know how to pick their battles. Due to the split-second reaction times required in space combat, Covenant fighter pilots use neural interface-based controls to avoid input lag.

The Covenant's close-range fighter tactics the UNSC looking more into developing a compact orbital dogfighter. While the Longsword excelled at long ranges, it was deemed too large and clumsy to contend with Seraphs and Banshees dropping right on top of them. One of the things hampering UNSC fighter development was the fact that many naval officers were not convinced that smaller nimble fighter craft were necessary to the war effort. Most of them saw fighter development programs as boondoggles that diverted resources from more important projects. However, other officers, particularly those who had flown the Longsword and similar craft into battle, pushed for the development of space-based strike fighters as a counter to Covenant close-range fighter tactics. They were joined by UNSC Aerospace Force officers who really wanted a small and agile fighter that could take the fight out of the atmosphere. As long as Seraphs and other classes of strike fighter could climb above an air-breathing vehicle's operational ceiling, the Aerospace Force were at a disadvantage. While smaller aerospace craft such as the Nandao existed, they were likewise designed for engagement at ranges far longer than those favored by Covenant pilots and were easily bested by Seraphs in an orbital fight. This led to the development of the Sabre, often regarded as the UNSC's first dedicated "vacuum dogfighter".

Aerospace fighters
Aerospace fighters operate primarily within an atmosphere, with air-breathing jets as their primary engines, though some examples are capable of limited vacuum flight (usually with a dedicated rocket or hybrid rocket-scramjet engine with enough fuel for a return trip to low orbit for a carrier rendezvous). Aerospace fighters are mainly designed to eliminate dropships, shuttles and other logistics craft, as well as enemy fighters. Their exact mission profile depends on whether they are on the defensive or offensive; defending aerospace fighters may be launched from the surface or orbit, whereas those deployed to assault planetary targets under hostile control are deployed from space, typically as a carrier enters orbit.

They are an important asset of aerospace control, as larger starships cannot descend too far down into a gravity well. However, their effectiveness decreases the further out of atmosphere you go, and in deep space they are easily bested by dedicated gunboats and outright warships, whose point defenses and missiles are able to pick off incoming fighters before they can do much damage. Aerospace fighters often use launch-assist systems when conducting an orbital mission from a planet; launching from an Earth-sized planet is very taxing for a fighter's propellant reserves, which will limit the craft's mission endurance once in space. This limitation also led to aerial fighters and space fighters initially developing as separate categories, as removing the requirement for surface-to-orbit transfers made dedicated space fighters far more versatile in their own element.

The UNSC Aerospace Force fields an array of aerospace and atmospheric-only jets, many of which are rarely seen outside planetary garrisons as the UNSC Navy favors more generalist craft.

UNSC
UNSC fighters are named after types of sword or birds; as a general rule, the former are more common for space-capable craft. Drone fighters have more varied names, though common themes are knives, daggers and throwing weapons.

All branches of the UNSC use a consistent letter-based designation system for their air- and spacecraft:
 * F = aerial or aerospace fighter
 * S = space fighter
 * FSS = aerospace strike fighter
 * R = reconnaissance craft
 * AV = attack VTOL
 * DS = unmanned space combat vehicle


 * Manned fighters
 * S-14 Baselard — a 25th-century aerospace strikecraft mainly used for orbital engagements and limited deep-space interception missions. Though capable of landing on planets, its maneuverability in atmosphere is limited and it requires booster stages to climb to orbit. Mostly replaced by the Longsword and the Sabre during the Human-Covenant War, and now mostly found in planetary defense forces.
 * F-41 Broadsword — an atmospheric fighter and ground-attack craft with limited spaceflight capabilities developed during the UNSC-CMA Cold War. Capable of being inserted from orbit, but requires external launch aid for STO.
 * S-77 Crow — an older, lightly-armored space fighter and patrol craft. Initially in service with the Aerospace Force, it later became popular in the commercial sphere as a short-range convoy escort and anti-piracy craft.
 * S-700 Longsword — introduced in the later years of the Insurrection, the Longsword is the UNSC's mainstay general-purpose fighter-bomber. A high-endurance craft, the Longsword is able to perform a wide variety of missions, which makes it ideal for Navy use. It is capable of a single SSTO transit and fairly substantial subsequent operation, and is able to perform deep-space incursions. Short interplanetary missions are theoretically possible, they are usually non-feasible without the use of cryotubes due to the limited onboard provisions. Several variants of the Longsword exist for different mission profiles, such as the S-708, S-709 and the S-712. A more recent S-718 model has emerged in the post-war era in select battlegroups.
 * F-29 Nandao — a small, fast and nimble aerospace strike fighter specialized in extending a carrier's force-projection capability into a gravity well and atmosphere, possessing the capability for a single dip into an atmosphere and back. Used in anti-fighter and anti-dropship roles as well as eliminating surface-based targets.
 * FSS-1000 Sabre — a small and super-maneuverable orbital defense craft developed in response to Covenant fighter tactics in the late 2540s, the Sabre is space-optimized and designed to use external booster stages to climb to orbit to save onboard reaction mass, but can re-enter and land on its own.
 * F-19 SkyHawk — an air-breathing jump jet in service with the Aerospace Force, the SkyHawk can act as an interceptor and ground-attack craft.
 * R-74 Swift — the Swift is a high-endurance reconnaissance and electronic warfare craft with limited stealth capabilities. Though in use for the better part of the 26th century, the Swift is an aging platform and may in time be replaced by a specialized Longsword EW variant.


 * Unmanned fighters
 * DS-32 Hurlbat — a drone strikecraft primarily armed with missiles. Commonly known as a missile bus and considered little more than a glorified missile in itself.
 * DS-49 Katar — a space-based compact attack drone relying more on numbers and maneuverability than heavy weaponry.
 * F-99 Wombat — an atmospheric combat and reconnaissance drone fielded by the Aerospace Force and various planetary defense forces.

Covenant
Although the Covenant have their own names for their fighter craft, the most well-known are the UNSC ones, which are based on angelic beings and mythical creatures.
 * Gigas — an older model of fighter-bomber.
 * Banshee Interceptor — light fighter / skirmisher craft; larger cousin to the Banshee ground-attack craft. Limited to space-only operation.
 * Seraph — general purpose fighter-interceptor. Capable of both vacuum and atmospheric operation (including surface bombing missions), though handles more sluggishly in atmosphere.
 * Tarasque — heavy fighter capable of being used as a bomber or even a dropship.