In 2001, Defense Department planners began searching for something that could hit a foe almost instantly without risking a nuclear holocaust. Most of the solutions -- unmanned bombers, faster cruise missiles, hypersonic "glide vehicles" coasting in from space -- required a decade or more of development. The Navy, however, had been testing conventionally armed Trident II missiles since 1993. With a few hundred million dollars, strategists said, the first Prompt Global Strike submarines could be ready to go in just two years.
The $60 million conventional missile needs to be far more accurate than the nuclear version. But the multiple warheads can lock onto GPS coordinates while streaking through space. Upon entering the atmosphere, the warheads use flaps to steer to a target. With the Trident II's range of 6000 nautical miles, subs armed with the missiles could threaten a whole continent's worth of enemy positions. "Now," says Benedict, who leads the Trident conversion effort, "we've got the capability to hold all of these targets in all these hot spots at risk at one time."
In 1988, Lockheed Martin's Trident II D5 nuclear ballistic missile entered service on Ohio class submarines. In the Prompt Global Strike program, each sub would be armed with 22 nuclear Tridents, along with two retrofitted Tridents, each with four independently targetable warheads. here's how a conventional Trident II would work.
1 Gas pressure ejects the Trident II from a patrolling submarine. Once the missile clears the water, the first-stage engine ignites and the aerospike at the nose extends to improve aerodynamics. Stage 1 burns for approximately 65 seconds. When the Trident is locked onto targets at its maximum range (roughly 6000 nautical miles), this burn carries the missile a few hundred miles downrange at a 45-degree angle. Because all propellant must be used, the missile corkscrews to burn off excess fuel for closer targets.
2 As stage 1 falls away from the missile, the second-stage engine ignites for another 65-second burn that carries the Trident an additional 500 to 800 miles downrange. The nose cone fairing (blue) is ejected to shed weight.
3 After separation from stage 2, the third stage engine burns for approximately 40 seconds, concluding the boost phase and lofting the Trident II up to 600 miles above the Earth -- the altitude of some weather satellites.
4 At the apogee of the Trident's trajectory, the third stage falls away, leaving the post-boost vehicle, or bus (red). It receives navigational updates and deploys the four individually targeted warheads (green). Traveling at 13,000 mph and accurate to 30 ft., the warheads are GPS-guided on descent by means of tiny flaps. Two types of warheads are under consideration: the fragmentation version, which shatters tungsten rods just above a target, and a bunker-busting metal "shock impactor" that relies on kinetic energy for its destructive power.
Exactly how is a 30ft accuracy CONVENTIONAL warhead more destabilizing than a nuclear one which has a FAR higher PK against hardened targets? (30 ft with a conventional warhead against a hardened target is effectively a miss.)
