The Space Force United States Marine Corps (USMC) is a branch of the United States Armed Forces responsible for providing power projection from space, using the orbital supremacy of the United States Space Force to rapidly deliver combined-arms task forces. It is one of eight uniformed services of the United States. Created in 2051, the Space Marine Corps has been a component of the United States Department of the Space Force, and works closely with space forces for training, transportation, and logistics.
Conceived shortly after the establishment of the Space Force to provide space to surface deployments of forces, at the time aimed primarily at lunar combat, the Space Marine Corps consisted largely of US Marine Corps Force Recon operators with extensive experience in space based combat. These operators were to directly engage enemy forces in space as well as deploy to terrestrial targets.
The first operation conducted by the new branch of the military was the defense of the Tycho shipyards. A group of US Force Recon Marines experienced in microgravity operations were transferred over to the Space Force and quickly deployed to secure Tycho from Japanese invasion, retake the city of Armstrong, and wipe out the Japanese military presence on the Moon.
Following the operations on the Moon, the Space Marine corps spent the remainder of the war deploying from orbit to combat Coalition forces on Earth, most famously at the Battle of Vancouver against Japanese interests in North America, and at the Battle of Beijing. Since the end of the Third World War, the Space Marines' ranks have surged to become the largest single force in the Earth Sphere, deploying globally to secure American interests.