Finally, Arming ICBM's With Conventional (Sort Of) Munitions For Devastating Rapid-Reaction Strikes

Seems like a no-brainer. We've got an awful lot of these doing little good -- they won't be toting a nuke warhead anytime soon, alas -- and they could be redesigned for more likely missions.

Within 2 minutes, the missile is traveling at more than 20,000 ft. per second. Up and over the oceans and out of the atmosphere it soars for thousands of miles. At the top of its parabola, hanging in space, the Trident's four warheads separate and begin their screaming descent down toward the planet. Traveling as fast as 13,000 mph, the warheads are filled with scored tungsten rods with twice the strength of steel. Just above the target, the warheads detonate, showering the area with thousands of rods-each one up to 12 times as destructive as a .50-caliber bullet. Anything within 3000 sq. ft. of this whirling, metallic storm is obliterated.

If Pentagon strategists get their way, there will be no place on the planet to hide from such an assault. The plan is part of a program — in slow development since the 1990s, and now quickly coalescing in military circles — called Prompt Global Strike. It will begin with modified Tridents. But eventually, Prompt Global Strike could encompass new generations of aircraft and armaments five times faster than anything in the current American arsenal. One candidate: the X-51 hypersonic cruise missile, which is designed to hit Mach 5 — roughly 3600 mph. The goal, according to the U.S. Strategic Command's deputy commander Lt. Gen. C. Robert Kehler, is "to strike virtually anywhere on the face of the Earth within 60 minutes."

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The Navy... 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."

And if that doesn't grab you, there's the X-51 WaveRider:

With an angled nose, flaps in the middle and an inlet on the underbelly, the device looks like a cross between a spaceship and a futuristic cruise missile. It's designed to go nearly seven times faster than a Tomahawk — a flight from the Arabian Sea to eastern Afghanistan would take 20 minutes — and destroy targets with its own kinetic energy. Test flights are scheduled for 2008.

The pressure, drag and high temperatures associated with hypersonic speeds (typically, greater than Mach 5, or 3600 mph) used to be considered too extreme for an aircraft to handle in a controlled way. Only ballistic missiles and spacecraft burning rocket fuel, shooting into space and roaring back to Earth, could go that fast.

What the X-51 does is to turn some of the most brutal effects of hypersonic flight to its advantage. Take shock waves, for example. Bursting through the air at a hypersonic rate produces a train of waves, one after the other, which can drag down an aircraft. But the X-51 is a "wave rider," with a sharp nose shaped to make the waves break at precisely the right angle. All of the pressure is directed beneath the missile, lifting it up. The shock waves also compress the air to help fuel the X-51's combustion process.

The craft is the same size and shape as a Joint Air-to- Surface Standoff Missile, so it can be attached to a B-52 or fighter jet. It runs on standard JP-7 jet fuel, not on rocket fuel, so it fits in neatly with the military's existing logistical chain. The X-51 is made from a fairly standard nickel alloy, not from exotic materials. And the advanced engine technology is very real. In 2004, NASA broke speed records while testing its X-43A, a precursor to the X-51 (see "Breakthrough Awards 2005," Nov. 2005). In a final test flight, the 12-ft.-long aircraft hit 7000 mph — nearly Mach 10. In other words, the X-51 is not just some lab experiment; it's being designed from the start to deploy. "I've got tremendous confidence in it working," the Air Force's Mark J. Lewis says.

That doesn't mean the X-51 will be in competition with a conventional Trident. It will have a range of only 600 nautical miles. And it first needs to be lifted into the air by a plane, then accelerated by a rocket-fueled booster before its hypersonic engine kicks in. But if the 2008 test flight is a success, the X-51 will be the first weapon other than a ballistic missile to fly at hypersonic speeds.

posted by Ace at 01:57 PM

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