The United States Space Command was framed as its own branch of service shortly after the colonization of Mars. It was created from the combination of all of the inter-services (Army, Air Force and Navy) space commands that were committed to near-earth security and given the role of interplanetary and later interstellar security.
In many ways it is structured similar to the United States Navy. The cornerstone of its power comes from space-based attack carriers and battleships. The United States Marine Corp was also expanded to accommodate the extrasolar needs of the space command while still maintaining its traditional security roles on Earth.
Primary command and control of this organization is located at the Pentagon. However, emergency command facilities are maintained at Mars and Barnard’s Star.
There are five components that make up the Space Command. The Space Force, which conducts the operational missions of the service. The Space Force Reserve, which maintains an inactive roster of personnel and equipment that can be activated quickly as required. The Fleet Marine Force, is composed of Marine units that are permanently assigned to the Space Command. The Expeditionary Command, is composed of rapid response forces which include extraterrestrial and terrestrial assets. Lastly, the Extrasolar Merchant Marine, which provides logistical support in a paramilitary capacity.
The USSC maintains and supports twelve fleets composed of over two-hundred sixty combat ships. Eight of these fleets are traditional space fleets headquartered as follows: 1st and 2nd Fleets are at Sol; 3rd Fleet at Rigel Kentarus A. 4th Fleet at Struve 2398. 5th and 9th are at Epsilon Indi, and 6th and 7th Fleet are a Barnard’s Star. The four expeditionary fleets are located as follows: 11th Fleet is located at Sol. 12th Fleet is located at Epsilon Indi. 13thand 15th Fleets are located at Barnard’s Star. Each of these expeditionary fleets have a Marine Expeditionary Force attached to it.
Each space fleet is broken down into two battle groups. Each battle group consists of a carrier, three cruisers and eight destroyers. The expeditionary battle groups have one battleship, two assault ships, three cruisers and eight destroyers. Each battle group is supported by numerous logistical assets, which include military and merchant marine transport, repair, auxiliary, salvage and medical ships.
The USSC is a robust organization that can be found operating in every US owned star system and beyond. It is also the largest branch of service in the United States.