Evolution of Ordnance Subsystems and Components Design in Air Force StrategicMissile Systems

摘要

Ordnance subsystems and components are critical elements in intercontinentalballistic missile (ICBM) systems. Since the early 1960s, the U. S. Air Force has successfully fielded four ICBM systems, these being the Minuteman I, II, III and Peacekeeper systems. Each ICBM system included three solid booster stages, an optional liquid propellant post boost propulsion system, a guidance and control system, and reentry vehicles (RVs). Ordnance is required on these systems for stage ignition, stage separation, thrust vector control system actuation, fluid isolation valve actuation, battery actuation, thrust termination, and RV release. The similarity between these ICBM systems enabled the development and evolution of ordnance designs. However, this approach did not prevent the programs from adopting new technologies to improve performance. For example, high temperature resistant HNS explosive was adopted and the through-bulkhead initiator and exploding bridgewire initiator replaced the hot bridgewire-based devices and detonators. In the Small ICBM, a laser/fiber-optics based ordnance firing system was developed with added built-in test capability to completely eliminate the bridgewire-based devices and their associated electrical hazards. Improved processing technologies were adopted for achieving a longer service life for explosive devices Better methods were adopted for ordnance testing; examples are the thermal-transient pulse test for hot bridgewire squibs and detonators and the built-in reflectometry for testing of laser ordnance. These approaches dramatically improved reliability, safety, weight efficiency, service life, and cost effectiveness. This paper reports the trends and the needs of the evolution of the ordnance subsystems and components with the emphasis on technology availability, maturity, and the payoff.