Multi-Stage Missile

The Multi-Stage Missile (MSM) is a varient of space-based anti-ship missile incorporating the ancient concept of staging, using multiple redundant engines to dramatically boost range.
==Concept and history==
While in space any weapon can have a theoretically infinite range due to the utter lack of friction, in practice this is impractical for use in war. Many armchair strategists have insisted that missiles could expend their fuel rapidly after launch to give them a terrific coasting speed, and attacking the target on a ballistic course. While possible, this leaves missiles exceedingly vulnerable to point defence fire as they cannot manoeuvre to dodge. Similarly, missiles can also not alter course to track an evading target if all their fuel is used up. Therefore, throughout history most space warship commanders have elected to close to a range with the enemy where missiles can be powered all the way to their targets, ensuring maximum effectiveness. Thus, throughout the history of Human space warfare, militaries have always sought to increase the fuel and engine efficiency and acceleration of their missiles to give them the range advantage. This was seen most clearly during the Insurrection, where both the UNSC and rebels made heavy use of missiles against each other. The UNSC's development of the RIM-438C Archer missile in 2512 resulted in a weapon that had superior range compared to the older 438B Missile and the Insurrectionists' shorter-ranged pirated RIM-397 Ares missiles and close-range rockets. This won the space campaign for the UNSC and resulted in the rebels shifting to more ground-based paramilitary and terrorist tactics.
However, the First Great War seemed to see an end to this missile arms race: Archer missiles were utterly impractical for use against shielded Covenant ships, and even after the shields were brought down, they would have to be used in enormous numbers to break through Covenant hull armour, and at rates that would deplete a ship's complement of missiles in an inordinately short space of time. The future of Human space warfare seemed to be dominated by the Magnetic Accelerator Cannon and nuclear warhead.
However, the launch of the United Nations Space Command's Project EXCALIBUR gave the concept of missile warfare a new lease of life. Launched in a bid to develop new technologies to give the UNSC and edge over the Covenant's massive numerical and technical superiority, Project EXCALIBUR saw the creation of the RIM-442 Anubis EMP missile, which proved to be astoundingly effective at bringing down Covenant shields in preparation for a missile or MAC strike, the RIM-332 Azrael nuclear shaped charge missile, which was used to great effect in puncturing Covenant hulls, and the RIM-441 Neith fragmentation missile, which exploited the holes in the hull created by the Azrael and shredded weaker interior decks. Since far more missiles can be launched at a target in any given period of time than shells from a MAC gun, this new missile superiority prompted the creation of the Invincible- and Retribution-class of arsenal ships, as well as the development of the Multi-Stage Missile.
The principle used in the MSM is that of multistage rocketry, a concept which had been condemned to the ash heap of history after the development of space elevators and EHD lifter drive-based launch vehicles. The result of staging is effectively two or more engines stacked on top of or attached next to each other. By jettisoning stages when they run out of propellant, the mass of the remaining stage or stages are decreased. This staging allows the thrust of the remaining stages to more easily accelerate the missile to its final speed and range.
==Design==
The basic design of an MSM is that of the missile's payload and sensor equipment on top of the primary Hall effect thruster and its propellent, which is in turn mounted on top of a second thruster and propellent, which breaks away after the propellent is spent. By jettisoning stages when they run out of propellant, the mass of the remaining stage or stages are decreased. Hall effect thrusters were chosen over more efficient engine types such as the Fusion Drive System (FDS) used by the earlier Archer missile due to their considerably smaller size and comparatively high thrust to fuel consumption ratio for their size (a reduction in mass results in an increase in manoeuvrability, a key consideration in missiles). The thruster's propellant is bismuth, and since ions are neutralised in the plume, the MSM is stealthy and difficult to detect with, for example, magnetic anomaly detectors.
This staging allows the thrust of the remaining stages to more easily accelerate the missile to its final speed and range. This system increases the range of the missile by a factor of two at the least. The missile can also coast between stages on a ballistic trajectory, while altering its course with side-mounted reaction thrusters in the target evades, further increasing the range of the missile. A disadvantage to this system is the more stages included in the design, the larger the missiles, and as such missiles mounting a tertiary stage, allowing truly phenomenal ranges to be reached, can only be carried by larger ships such as battleships and carriers. In 2565, a four-stage missile was being developed by the UNSC Navy, a project which was accelerated after the outbreak of the Second Great War, but its increased size also necessitated the design of a new class of arsenal ship, the King Arthur-class.
==Missiles incorporating MSM technology==
*RIM-441 Neith
*RIM-332 Azrael
*RIM-446 Poseidon
*REM-225 Eris
*REM-226 Gungnir
Category:Weapons
Category:War of Vengeance
Category:Labyrinth
Category:Naval weapons of the UNSCDF