High-Speed Marine Dropships
Essentially a missile that drops the Marines to the surface of a planet without turning them to jelly.
Only lightly armed, has controlled flight for Marine exit, but is designed for a quick drop. Strong hull/armor, but no weapons systems to speak of.
Controllable in low atmosphere should the intended LZ get too hot to drop before it gets there.
Approximately 30 seconds of drop time from high-atmosphere to ground.