Guardians of the Stars
Military Ground Vehicles
Military Ground Vehicles covers a large range of vehicles used by military forces in combat. This omits support vehicles that do not actually fight in combat. Several different vehicles fit into this class: Tanks, Infantry Fighting Vehicles (IFV), Armored Cars/Trucks, and Mobile Artillery.
The concept of the ‘tank’ has existed since World War I on Earth, however historic imaginings that fit the concept go back thousands of years. Certain trends are seen within each era.
During the Early Space Era tanks were still mostly fixed tracked vehicles with a large turret on top of the chassis. Tanks typically fall into one of three classes: Light Tanks, Medium Tanks, and Main Battle Tanks/Heavy Tanks. The difference between the three types is mostly in the size and mass. Most tanks during this era use conventional Ectrothermal-Chemical (ETC) cannons with railguns still being to large and power hungry to meet the needs of tanks. Many tanks still use gasoline or diesel fuels as their primary power sources, however some begin to use Compressed Natural Gas (CNG) as an alternative fuel source.
The Interstellar Space Era continued the trend from the earlier era. The biggest change is in adding several tanks with armored wheels rather than tracks. Many tanks of this era also operate on different engine and power systems then earlier designs. Electrical motors and large power cells are not unusual, fuel cells with electrical motors is another common option. The few tanks still using combustion engines make use of CNG as a fuel. Railguns begin to replace ETC cannons as primary weapons for tanks and some anti-infantry weapons also begin to use railgun techniques.
The Modern Space Era changed all the rules for tanks. Fixed tracks have been replaced with split tracks and rather than wheels on lighter tanks low height hovering is used. Most hover tanks are what would have been classed as light tanks and sometimes even still are called that. It requires more energy than is currently possible to provide heavier tanks with hover abilities. Tanks also move beyond batteries and fuel cells and small fusion reactors become common within tanks providing considerable power for weapons and locomotion. Railguns are standard weapons and more power hungry weapon systems are being experimented with.
Infantry Fighting Vehicles
Infantry Fighting Vehicles fill a large range of vehicles, in fact all armored cars and trucks are usually in this category. This category also includes Armored Personnel Carriers (APC), Infantry Combat Vehicles (ICV), Scout Cars, and Missile Trucks.
The Early Space Era includes a variety of tracked or wheeled vehicles. Most are lightly armed and lightly armored compared to tanks, but can carry infantry forces larger than a tank carries. They are also usually manned and operated by infantry with proper training. Combustion engines using gasoline, diesel, and CNG are the order of the day.
During the Interstellar Space Era IFVs did not change in form very much, but they did explode into a range of new designs filling new or changed battlefield niches. The Drifter IFV even fell into use as a tank by combining the abilities of IFVs with heavier armaments. Combustion engines for IFVs almost all exclusively use CNG during this era. Most convert to electric motors using batteries, fuel cells, and even small fusion power plants as power supplies.
The Modern Space Era adds a new form of locomotion: Hover capability. This is just like the change seen in tanks and the reasons are similar. Most IFVs during this era still use armored wheels or tracks however as they are less energy intensive and easier to work with. Locomotion is universally by electric motors with power provided by small fusion power systems, though some other forms of energy production and storage may also be used. Railguns are also the standard weapon for many IFVs with earlier conventional and ETC weapons being phased out.