Macro-gun

The Macro-gun family of weapons is one of the primary heavy armaments of capital ships of the Union Armada.

Description
The Macro-gun is a large warship mounted kinetic weapon and a natural evolution of naval rifles from ancient history. They are at their simplest a combination of light gas guns and coilguns, but most also have additional components included to squeeze out as much muzzle velocity as is physically possible. Every Macro-gun contains three sub-sections: a light gas gun section, a transition section, and a coilgun section.

The projectile to be fired receives an initial velocity from its light gas gun section. A chemical propellant charge (usually a solid fuel or a shaped charge) accelerates a pusher plate down a long tube filled with hydrogen and oxygen, rapidly increasing the interior pressure and heating up the gas. When the pressure reaches a point where the seal blocking the gas from the transition section ruptures, an electric arc ignites the gas mixture. The resulting rush of super-pressurized burning gas pushes the projectile, located in the transition section, up to an initial velocity. The projectile then enters the coilgun section where a series of magnetic coils pull at the projectile to bring it to higher speeds.

The coilgun section of a Macro-gun is usually also filled with a hydrogen-oxygen mixture. By exploiting the same physics that allow ramjets to accelerate without many moving parts, with the projectile serving as the central compressor ram, yet more kinetic energy can be imparted into the projectile. Sensors all along the Macro-gun’s barrel measure the velocity of the projectile and fine-tune the timing of the magnetic coils for optimal performance. The result is a muzzle velocity easily in the range of dozens of kilometers per second and a giant gout of combusting gas rushing out the muzzle of the Macro-gun.

The forces required to accelerate projectiles in the mass range of a metric ton to velocities sufficient for space battle imparts huge amounts of kinetic and thermal strain upon the barrel of a Macro-gun. To compensate for this, gun barrels usually include a series of rib-like stiffening rings that double as radiators.

Unlike the Lance, the Macro-gun does not have many patterns that confer unique effects in battle. Most patterns differ only in more mundane details such as munition caliber. The application of unique effects rely not on the Macro-gun but rather on the munitions it fields.

Naming Convention
The MRAV Index recognizes the Macro-gun by this name and by names such as “Macro-artillery”, “kinetic artillery”, and other similar phrases that describe its mass-slinging nature and large size.

A battery of Macro-guns is called an “orchestra” and a collection of Macro-gun orchestras is called a “symphony”. This naming convention references an ancient research project “Harp” that produced a very early and simplistic iteration of what would become the modern-day Macro-gun.

Many scholars have pointed out that the weapon could conceivably be called a “macro-cannon”, in line with the naming conventions set by some of the aforementioned recognized names, but is not referred to by that name in any official documents. Some[who?] claim that this inconsistency is caused by the phrase “macro-cannon” being a copyrighted term from an Intellectual Property whose copyright protection remains in effect.

Ammunition Types
While Macro-gun patterns are relatively unexceptional in unique traits, the various types of ammunition they can fire can be quite exceptional.

Most Macro-gun munitions share a list of common modules to improve their performance. Examples include a solid propellant engine at their rear, similar to those on the Sprint terminal ballistic defense missiles, to allow for even more acceleration and some basic direction control; internal metal coils to help the coilgun solenoids secure a better “grip” on the munition; delta-V resistant electronics to control the aforementioned engine; and ballistic caps / heat shields to allow the munition in question to be used against objects at the bottom of a gravity well with an atmosphere.

Macro-gun munitions usually differ in the manner by which they deal damage to a target.

5M33 "Super Heavy"
The “Super Heavy” operates on Newton’s laws of motion. They damage enemies primarily through the kinetic energy each of these one metric ton heavy projectiles can deliver. Some may contain an explosive filler to increase post-penetration damage, however the effects of this filler are relatively minor relative to that of a successful hit.

On direct impact the munition smashes through armor and structure with the grace of a speeding train, spalling into a hail of metal fragments in the process. At these velocities armor angling matters less than it might in terrestrial applications; brute strength of the armor in question becomes more relevant. The kinetic impact rattles the area around the point of impact, compromising structural integrity and causing interior surfaces to eject spall fragments from the forces involved. Internal spaces unfortunate enough to be penetrated experience an amount of spall large enough to destroy almost anything that might be present within.

While Super Heavy munitions are harder to deal damage with compared to other ammunition types, owing to their need for a direct impact across the vast distances of space warfare, they also require much less resource and effort to manufacture. To this end they are usually reserved for enemies that cannot run away, such as large space stations.

5M43 "Fireball"
The “Fireball” carries a nuclear payload in place of a chemical explosive filler. Each Fireball can carry either a single fission/fusion munition of up to 500 kilotons TNT equivalent or up to 12 pure fission submunitions of up to 20 kilotons each.

On detonation the payload(s) turn into one or more blinding flashes of X-rays emanating outwards in all directions. Targets close enough to the atomic flash rapidly heat up from high energy photons bombarding their surface, with those too close heating up at such a rapid speed that their surface layers violently boil off. The force of this vaporization causes secondary kinetic shocks to rattle the target, much like the impact of a “Super Heavy” shell but distributed across an area instead of focused on one spot. The glowing hot surfaces may remain incandescent for some time, depending on how fast they can dissipate away heat.

As impressive as these effects may be, they still do not solve the fundamental problem with Super Heavy munitions. The effective radius of a “Fireball” projectile is usually measured in the low kilometers, an improvement over point-attack but still severely lacking. The omni-directional nature of the “Fireball” wastes most of its potential; the X-ray flash radiates outwards in all directions while the enemy is usually located in one specific direction

5M68 "Casaba-Howitzer"
The “Casaba-Howitzer” resolves the wasteful nature of the “Fireball” by directing much of its energy into a narrow beam of super-accelerated (even for Macro-gun standards) plasma.

The standard “Fireball” ammunition contains a fission core surrounded by a fusion blanket, with the detonation of the former compelling the latter to fuse and radiate X-rays in all directions. The “Casaba-Howitzer” replaces the fusion blanket with a filler that absorbs the fission core’s energy and holds on to it for a miniscule fraction of a second. The filler transfers some of this energy into a specially shaped liner, and the uneven heating of the liner (and its resulting uneven thermal expansion) rapidly accelerates its constituent atoms forwards of the “Casaba-Howitzer” at extreme (for other Macro-gun munitions) velocities. The same science that functions in conventional chemically initiated shaped charges also apply here, but with much higher energy scales at work.

The plasma beam generated by a “Casaba-Howitzer” ammunition has an effective range of a few dozen kilometers before the uneven forces exerted upon it cause it to disintegrate. This puts the kill distance of the “Casaba-Howitzer” outside of the most powerful and intense point defense areas of most ships, allowing the munitions to be much more survivable while not sacrificing much damage.

5M103 "Excalibur"
The “Excalibur” is the final iteration of the Macro-gun ammunition tech tree, the most expensive of them but also the most powerful and capable. Instead of accelerating beams of plasma to a small fraction of lightspeed, the “Excalibur” directly generates X-ray lasers that travel at the fastest speed information can attain.