A quick sketch of a Roman Republic Monitor, 2200 AUC, for my second novel.
Monitors fulfill the variety of roles demanded by the Roman Republic's doctrine: the defense of the system, the biosphere, and the Republic.
Having just barely survived what could be vulgarly described as a "Corporate Venture" by an alien species thus named the Tenebrae in 2000-2001; the Roman Republic, which had been competing in space by the now defunct Alliance of Nations, reaffirmed the strategic field. They were not alone. Life was hostile. They were weak.
By 2005, ten "Armed Scout Ships" were approved and made by the Department of Space to patrol the holdings of the Republic, and then as a probe program, launched in 2030, reported back in 2080 that the closest system to Sol, the Three Siblings, had an viable, space-faring civilization (which were not the Tenebrae), the military build up and the launching of a fleet in 2100 only reinforced the Xenophobic attitude of the Solar System. When that fleet, arriving at the three brothers in 2154, reported that their surprise attack had destroyed that nascent civilization in 2159, the Republic felt secure, and what could only be described as a political-social climax ended and the system started to slide into corporate, criminal, and regionalistic conflicts, with the government and military - having always been close from after the invasion in 2000 - became a walled off faction.
The Monitor shown here was of the latest class, developed in the 2190s, a development of a earlier type made in the 2150s. Quick and fast, they were stationed at points of governmental interest and could not patrol much - but they didn't had to. The main points of worry were the tanker-lines from the outer gas giants - Neptune, Uranus, Saturn - to feed the energy demands of the civilization; the depots of fuel, IPN communication relays, and to maintain the Republic as a governing body. Each of the five first tier divisions - Venus, Earth, Mars, Ceres, Chariklo - had an attached task force of up to thousands of ships, split into active, garrison, and reserve divisions.
They would be tied down to depots and bases and points of interests, and would engage any approaching enemy - alien, criminal, or rebel - use their superior numbers to knock out the enemy, or force them to withdraw and rout - and then return. Corporate warfare, as well, took a focus of the military as the huge economy became intertwined, and sometimes entire squadrons would protect, destroy, and harass other corporate entities due to a rising Plutocracy in lieu of the old Military Junta. Advanced fabrication, resource collection, and the diffusion of technology allowed many middle and large sized groups to have the ability to make and own ships, and conflicts became more and more common.
This class of Monitor has one crew member, a brain which is supported by advanced computers. The brain, already cyborgized due to military prerequisite, is simply taken from the body at the bases and inserted into the ship. This drastically cuts down on needed expenses towards life support, since a brain needs much less than a full body, removes the need for auxiliary craft, and allows more of the ship to be focused on the laser system, huge as it is to provide an efficient engagement envelope of around 200KM.
Such a system had been in place as quickly as possible, starting from the 2020s to cut down on costs of mass and all issues stemming thereof, and by training regimens and specialization, crew numbers decreased until the brain is just there to pilot, coordinate, and maintain control over the craft itself. Missions of combat tend to be in the matter of hours and up to a day or so, not much more, and never really needed, though current doctrine states that if a operation of days is needed, to use the fuel depots, or upgrade the life support and coast; through if an faction is months away, or a whole planet breaks off, the much unseen Cruiser ships and fleets might be used instead.
Operating always in groups of ten, divided into two sections, they typically are spread out at 100-200KM apart, and it was coordination, charges, jousts, and the like which won the day by either destroying the crew module or the radiators of the reactor, laser system, or life support to force a withdrawal of singular elements until one side can no longer fight. Battles tend to be bloody and costly as crews are trained to take out enemy crew, along with their lasers, radiators, and there is never a guarantee a fleeing ship, or a hit ship, will be left further unscathed.
And as political conflict turned into a civil war in 2200, and later again in 2245, not to mention the constant conflicts of corporations and cultural groups, this class of Monitor saw plenty of blood throughout their service, whatever their class.