The Republic of Texas Marine Corps are not infantry. Ask them. They will be quick to disabuse you of that notion. They are Marines. They are trained to fight in space or on ground. They are trained in High Altitude Low Orbit drops from starships aboard assault shuttles, mechs, tanks, jeeps, cycles, or simply wearing the powered battle armor that is their uniform. When the fleets hold the orbitals, when the Army is planning an invasion, the Marines go in first to secure the landing zone, often in the face of planetary defense grids that do not wish them to come down alive. It is often Marine attack craft or starfighters that dive down with them, smashing the defenses or taking fire for their brothers and sisters. The Marines did this in countless small actions of the various brushfire conflicts out in the colonial regions that no major nation admitted went on. They ramped up during the Hyades Campaign and filled the skies with HALO Marine drops across the cluster.