Before revision: The Inertial Reference Unit from a Peacekeeper Inter-Continental Ballistic Missile (ICBM) The two basic classes of IRUs/IMUs are "gimballed" and "strapdown".
After revision: The inertial reference unit from a peacekeeper inter-continental ballistic missile (ICBM) The two basic classes of IRUs/IMUs are "gimballed" and "strapdown".