(This is part of our Ships of The Black Desert series. The maps below were done entirely in Adobe Photoshop Elements 5.0; not sketches were scanned as references. The mapping project took about 70 man hours to complete. Of course, I have three kids... )
Among the most successful space-borne designs to come out of the Great War, the RG-403 Heinlein was the backbone of Brazil's military machine. Even now, forty years after their initial release, the rocket is still considered by tacticians to be among one of the most innovative ideas in active space combat and continues to be the premier attack craft of the Union of the Americas. The combat effectiveness of the Heinlein is not based on its originality, however. The Heinlein rocket system is effective because it is so common that practically every major nation and organization has them.
The Heinlein was initially proposed as a solution to the stealth problem in space combat. Since before manned spaceflight became common, it was recognized that hiding the movements of military spacecraft would be impossible. Merely firing a maneuvering thruster on an orbiter creates a thermal signature that can be seen anywhere in the Inner System. This total lack of secrecy in spacecraft movement, when combined with the incredible speeds and distances involved in space travel meant that not only would an opposing wing of spacecraft know exactly how many of the approaching enemy there are, but would be able to maneuver to a new vector that made it impossible for the opposing wing to intercept. It was for this reason that the majority of the deep space theater of the Great War was stalemated during the initial years of the conflict.
Analysts for Brazil's Ministry of War concluded that the best way to counteract the lack of stealth in space was to use it to their advantage. There is only a short window of opportunity after the detection of an enemy's space wing to change vector; once that opportunity is gone, the two opposing space forces will intercept. Therefore, if an enemy's spacecraft could be fooled long enough for the maneuvering window to pass, the Brazilian fleets could engage them.
The Ministry decided that the best way to remain undetected for the required duration was for their military rockets to pose as civilian ones. Commerce raiding was as prevalent in the Great War as it was in any terrestrial conflict, and the Brazilian merchant fleet had sustained its share of losses from attacks against its convoys. The most common merchant rocket, Embraer's RG-403 (General Rocket, 40 meters, three winged) was chosen to undergo upgrades into a military interceptor.
The refitted 403s proved to be a nasty surprise for commerce raiders. The US and several Asian powers lost wing after wing of rockets to the depredations of Brazil's new war machine. The decreased loss of shipping from the commerce raiders' new found reluctance to engage merchant 403s was an added bonus.
Like all military innovations, the stealth of the Heinlein-class was short lived. The European Union and China acquired Heinleins and cloned the design, forcing Brazil to create elaborate codes and IFF transponders as a result. The Americans had been running an aggressive anti-South American propaganda campaign since the loss of their Ecuadoran space elevator and therefore militarized their own merchant orbiters instead of building Heinleins. This, of course, was less successful and the continued loss of colonial shipping further exacerbated their resource scarcity as the war ground on.
After the nuclear attacks and the ecological disasters that followed, many RG-403s were used simply to evacuate flooded and fallout-ridden areas. After the Treaty of Mars went into effect, the bulk of the Union of the Americas space command was sold off and became simple merchant ships again. Despite this, Brazil and her member states still use the venerable rockets for military purposes and the ubiquity of the design make them practically invisible as the rockets prowl the orbits of the asteroids in the Black Desert.