Development of earth-penetrating weapons

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New York Times Dec 3, 2001

U.S. Making Weapons to Blast Underground Hide-Outs

By ANDREW C. REVKIN

he Pentagon is hurriedly developing powerful new earth-penetrating weapons even as American forces are striking dozens of suspected underground hide-outs of Al Qaeda and the Taliban with specialized tunnel-blasting bombs and missiles.

Despite the current focus in Afghanistan, the main target has been not Islamist terrorists, but instead the nuclear, biological and chemical weapons programs in countries like Iraq and North Korea.

The new weapons go far beyond the now familiar "bunker buster," the GBU-28 laser-guided bomb that along with similar guided missiles has been used extensively against Afghan caves and tunnels.

Some of the new bombs, missile warheads and other armaments have already been built and tested, including a system called Deep Digger, developed by the Defense Special Weapons Agency for Special Operations forces.

This rapid-fire cannon, most details of which are classified, is said to eat into rock or reinforced concrete with a series of blasts, using secondary explosions to remove the resulting rubble quickly.

A version that could be sent into battle is being refined by Advanced Power Technologies Inc., a company in Washington with a branch specializing in new drilling and excavation methods.

Another weapon that is ready for combat is the AGM-86D, a refurbished deep-penetrating version of the Air Force's formerly nuclear- tipped aircraft-launched cruise missile. Last Thursday, the contractor, Boeing, said a missile launched from a B-52 bomber over the White Sands Missile Range in New Mexico had successfully struck "a hardened, buried target complex" and detonated inside.

The Air Force has received part of an order of 50 of the missiles, on which nuclear warheads had been replaced with a slender, heavy conventional warhead that can drive deep into the earth.

Other weapons designed for destroying deep targets are to be test fired at tunnel systems being built at the old Nevada Test Site, once used for studying nuclear weapon blasts underground.

A classified status report on buried threats and the need for new weapons was delivered by the Pentagon to the Senate Armed Services Committee about a week ago, Congressional staff members said.

Pentagon and elected officials declined to comment on the contents, but experts said the danger hiding underground abroad was growing.

"Long before we learned about bin Laden's caves, there were North Korea's caves," said Clark A. Murdock, who until last year was deputy director of long-range planning for the Air Force and now is a senior fellow at the Center for Strategic and International Studies, a private research group in Washington.

"The crown jewels increasingly are buried," he said, "and that's why people are thinking about these things."

A major goal, according to Pentagon documents, is to assemble by 2004 a small arsenal of weapons that can — with potent precision blasts — destroy subterranean complexes in North Korea that may harbor nuclear weapons or the missiles that carry them.

Another target is Iraq's many suspected underground installations, in which President Saddam Hussein may be hiding deadly caches of microbes, nuclear materials and chemicals.

Some government scientists and Bush administration officials want to add a small deep-diving nuclear weapon to the collection, one that could destroy a dictator's bunkers without releasing significant radiation.

But many political and arms experts say it is extremely unlikely that such a weapon would be approved by Congress or desired by military officers, who would rather have conventional weapons that require no presidential approval to use.

The next-most-potent weapon, a conventional warhead on a space- skimming ballistic missile, is also being studied by the Air Force.

The push to improve ground-penetrating weapons began after the Persian Gulf war of 1991 revealed Iraq's subterranean activities. It accelerated later in the 1990's as Libya, Iran, North Korea, terrorist camps in Afghanistan and other adversaries shifted activities underground to avoid attack and detection by satellites and aircraft.

In 1998 the Senate Armed Services Committee authorized extra spending on a new generation of weapons to fill what it said was "a critical gap in the capabilities of our armed forces."

The new weapons work builds on research that began in a flurry of improvisation after Iraq invaded Kuwait in August 1990. Indeed, many of the weapons being used now on tunnels and caves in Afghanistan had their genesis at that time, most notably the laser-guided GBU-28 bomb, created to plunge as much as 100 feet into the earth to destroy command bunkers.

The gulf war ended so quickly that only two were used, one of which clearly accomplished its task, according to later Defense Department reports: smoke was seen billowing from ventilation shafts of a command bunker shortly after it struck.

Now a variety of more potent weapons are being developed. Eglin Air Force Base in Florida has a Precision Strike System Program Office, which has tested a hard-nosed bomb designed to penetrate and incinerate buried caches of chemical or biological weapons without releasing contamination into the air.

Another proposed warhead, carried on a missile or bomb, would attack tunnels by piercing a reinforced door, then skipping several times down a passageway — keeping track of the bounces and detonating only when it was deep inside.

To save money and speed development, the Pentagon is focusing on upgrading existing bomb and missile designs with heavier, slimmer casings and computer-controlled fuses that allow them to punch deeper into the ground and precisely control the point at which they explode.

The most established example is the Advanced Unitary Penetrator. It is the heart of a new version of the laser-guided GBU-24 bomb and has more than twice the penetrating power of the previous hard-target warhead for that bomb.

It has a long, slim case made of a heavy, hard alloy of nickel, cobalt and steel, sheathed in a conventional aluminum fuselage that strips away as it collides with a target.

The combination of heavy weight and a small diameter concentrates enormous force that drives it through the earth the way a nail punches through wood when struck by a heavy hammer. The warhead had its first battlefield use in Kosovo in 1999.

A particularly potent weapon, being developed under a program managed by the United States forces in Korea, would attack North Korea's growing tunnel and silo complexes using high heat and deadly pressure. One proposed version would ride on a supersonic cruise missile.

The effectiveness of this "thermobaric" weapon lies in a new mix of highly explosive materials that when released and detonated in a tunnel create a long-lasting wave of high pressure that kills anyone or destroys equipment throughout a maze of passageways.

Fuel-air explosives of this sort have been widely used above the surface by the United States in the gulf war and by Russia in Chechnya. According to military documents, the above-ground blasts produce up to twice the pressure of conventional high explosive charges and searing temperatures above 5,000 degrees — far hotter than the fires that toppled the World Trade Center towers.

But getting underground is only the beginning. To guarantee an effective attack, the explosion — or multiple explosions in the case of several new weapons — must be precisely timed to occur at just the right moment or depth.

That is the job of the "hard target smart fuse," the newest computer- controlled fuse, which can, in the split-second as it strikes a target, discriminate between rock, concrete and soil and can also count, ticking off each ceiling or wall it strikes and only triggering the blast at the desired underground level.

The smart fuse controls several existing hard-target warheads, and Pentagon officials said they planned to use it to control a wide range of future weapons.



-- (Bill Murray @ Caddy.Shack), December 03, 2001

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Moles are mobilizing a counter-strike

-- (Rodney Dangerfield @ don't get no.respect), December 03, 2001.

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