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America's space-age missile defense Missile defence is an air defence system, weapon program, or technology involved in the detection, tracking, interception and destruction of attacking missiles. Originally conceived as a defence against nuclear-armed ICBMs, its application has broadened to include shorter-ranged  sounds like something out of Star Wars. But will it work?

This was only a test of the Pentagon's National Missile Defense National Missile Defense (NMD) as a generic term is a military strategy and associated systems to shield an entire country against incoming Intercontinental Ballistic Missiles (ICBMs). The missiles could be intercepted by other missiles, or possibly by lasers.  System -- with $100 million riding on the results.

Last January, a 60-foot-long American missile loaded with a mock warhead roared out of its silo on the central California Central California can refer to one of several divisions or regions of the U.S state of California:
  • The state is sometimes described as being in three main sections: Northern California (the San Francisco Bay Area and Sacramento Valley northward), Southern California (south
 coast. Seconds later, nearly 7,000 kilometers (4,350 miles) away in the South Pacific's Marshal Islands, another missile--this one an "interceptor"--streaked into the sky. Nestled inside the interceptor's nose sat the world's most sophisticated high-tech bullet: a 48.5 kilogram kilogram, abbr. kg, fundamental unit of mass in the metric system, defined as the mass of the International Prototype Kilogram, a platinum-iridium cylinder kept at Sèvres, France, near Paris.  (130 pound)-device known as an exoatmospheric kill vehicle Exoatmospheric Kill Vehicle (EKV) can refer to two related missile defense concepts:
  • Most common: the Raytheon-manufactured interceptor component with subcontractor Aerojet of the U.S.
, built to destroy enemy missiles in space before they ever reach the U.S.

Here's what was supposed to happen: Posing as an "enemy," the California rocket would soar 1,609 km (1,000 mi) above Earth and release its mock warhead plus a decoy DECOY. A pond used for the breeding and maintenance of water-fowl. 11 Mod. 74, 130; S. C. 3 Salk. 9; Holt, 14 11 East, 571.  balloon. In an actual nuclear missile, a burst of decoys would serve to lure an interceptor from its intended target. But through an arsenal of Star Wars-type gadgetry gadg·et·ry  
1. Gadgets considered as a group.

2. The design or construction of gadgets.

Noun 1. gadgetry - appliances collectively; "laborsaving gadgetry"
, the interceptor with its kill vehicle would hunt its prey at 241 km (4,900 mi) per hour and smash the warhead.

That's not what happened last January, however. Seconds before contact, the kill vehicle veered by 73 meters (241 feet) and missed. The $100 million test proved a real bomb.


Defense scientists say a blown cooling pipe may have caused the failure, but insist the U.S. needs to build the highly controversial $60 billion defense system. "The threat of nuclear missiles is suddenly a major concern again," says Mike Biddle, a U.S. Defense Department spokesman. That's because a few aggressive nations are trying to build nuclear warheads and the missiles needed to launch them. If President Clinton gives the go ahead this fall, the first 25 missile interceptors will be ready within five years. But will it spark a new arms race? Is the new system too pricey Pricey

Term used for an unrealistically low bid price or unrealistically high offer price.


Of, relating to, or being an unrealistically high offer. An offer to sell a security at $50 when the current market price is $47 is pricey.
? And will it even work? In the first three out of 19 planned tests--including a miss in the most recent test in July--the system has hit a dummy warhead only once.


If an enemy group or country were to attack the U.S., a missile carrying a nuclear warhead would take 30 minutes to reach and decimate dec·i·mate  
tr.v. dec·i·mat·ed, dec·i·mat·ing, dec·i·mates
1. To destroy or kill a large part of (a group).

2. Usage Problem
 a U.S. city. Warheads contain a nuclear bomb, which relies on fusion energy (the joining together under intense heat of two atoms to form a heavier element), the same force that fuels the sun. Hydrogen atoms (a gas, the lightest of all elements) fuse together, producing helium (another gas and the second lightest element). The fusion process releases vast amounts of energy. A typical one-megaton bomb detonates with a force equal to 1 million tons of dynamite at more than 111 million [degrees] C (200 million [degrees] F)--six times as scalding scalding

plunging of pig or poultry carcasses into very hot water to facilitate scraping and dehairing and plucking. Chicken scalding water is 130°F for broilers (larger birds higher) applied for 1 to 2 minutes. Modern pig abattoirs use steam at 144 to 147°F for about 3 minutes.
 as the sun's center.

Such a bomb would reduce everything within a 3.2 km (2 mi) radius to rubble and kill 98 percent of the immediate population almost instantly. Those living 8 km (5 mi) away might survive the initial blast, but nuclear bombs also release waves of radioactive energy (energy released when an atom loses particles from its nucleus). Known as fallout, the waves travel on wind currents, blanketing Earth with radioactive material radioactive material Radiation A substance that contains unstable–radioactive–atoms that give off radiation as they decay. See Radioactive decay.  hundreds of miles away from the blast. Exposure to fallout causes increased cancer rates and birth defects birth defects, abnormalities in physical or mental structure or function that are present at birth. They range from minor to seriously deforming or life-threatening. A major defect of some type occurs in approximately 3% of all births.  in humans.


Military scientists say a missile shield would block a nuclear attack. Here's how it would ideally work: When an enemy missile is launched, early-warning satellites 35,406 km (22,000 mi) above Earth detect its presence through infrared sensors that measure heat waves emitted by hot objects. The satellites fire location data to the U.S. Space Command's center inside Cheyenne Mountain Cheyenne Mountain, c.9,565 ft (2,915 m), in the Front Range of the Rocky Mts., El Paso co., central Colo., SW of Colorado Springs. Halfway up the mountain, in North Cheyenne Park, is the Shrine of the Sun Memorial, erected in memory of Will Rogers.  in Colorado.

Ground-based radar installations then track the missile. Thrusters propel nuclear missiles high enough into outer space to reach the U.S. from across the globe. Then the missile nose breaks apart into a barrage of warhead-like objects (see diagram, p. 17). All are decoys except for one nuclear warhead capable of catastrophic devastation.


Meanwhile special U.S. X-band radar X band is a radio frequency range designation that denotes the operational frequency of a specific radar system. X band is only one band among many; others include: S band, C band, K band, L band, and W band. X-band radar, itself has a variety of types.  tracks the warhead and decoys. (Conventional radar determines the position of distant objects by bouncing energy waves off them, but X-band radar beams high-energy waves that can reach outer space with pinpoint accuracy.) "It can be aimed like a flashlight," Biddle says.

Analyzing the radar data, computers in Colorado calculate when to launch a defensive missile, and at the precise moment, a U.S. missile blasts off in Alaska. After a three-stage burn, the boosters fall away, leaving only the kill vehicle. It's equipped with a pair of high-tech "eyes": two infrared sensors cooled to -184 [degrees] C (-300 [degrees] F). The sensors detect even the faintest heat in outer space, and an on-board computer uses algorithms--complex mathematical calculations--to distinguish between a real warhead and fakes.

The kill vehicle smashes the war head on impact. "It locks onto the warhead," says Ronald Kadish, director of the Pentagon's missile defense program, "and collides at a speed of 7.4 km (4.6 mi) per second. At that speed, there's nothing left of the warhead."


Scientists hotly disagree whether a missile defense system Noun 1. missile defense system - naval weaponry providing a defense system
missile defence system

naval weaponry - weaponry for warships
 would work. Many think a kill vehicle's sensors will never be accurate enough to distinguish between decoys and a nuclear warhead. Other critics say a nuclear shield is outrageously expensive and unnecessary. Still others believe the U.S. needs a complex missile defense system to avert the threat and destruction of nuclear war. What do you think?


The cornerstone of the President's $60 billion program to defend the U.S. from nuclear attack is an interceptor missile that would knock an incoming nuclear warhead out of the sky. Here's an illustration of how it's supposed to work:

enemy missile

Delivers one nuclear warhead and a burst of decoys


Warhead-like objects designed to fake out interceptors


The nuclear bomb--if it gets through, millions could die


Tracks the enemy missile and helps guide the interceptor missile.

interceptor missile

Releases the kill vehicle, whose high-tech sensors hone in on the enemy warhead


The kill vehicle makes a direct hit, smashing the warhead.

What if a Bomb Fell on New York City New York City: see New York, city.
New York City

City (pop., 2000: 8,008,278), southeastern New York, at the mouth of the Hudson River. The largest city in the U.S.

1. The initial blast blows open a 305 m (1,000 ft)-wide, 61 m (200 ft)-deep crater, demolishing all buildings and killing 955,000 people.

2. Nearly all buildings are destroyed; 750,000 people are killed, and 600,000 injured.

3. Buildings are destroyed or damaged, people and debris are thrown onto the streets; 25,000 die, 225,000 are injured.

4. Moderate building damage, few immediate deaths; flying-debris injuries; severe to fatal radiation doses.

A plume of radiation, or fallout, blows east over Long Island, killing many of the 2.8 million residents within two weeks. Some radiation could reach Boston or Washington D.C., poisoning millions more. Result: genetic damage, widespread cancer years later.

SOURCES: ATOMIC ARCHIVE (; THE EFFECTS OF NUCLEAR WAR, WASHINGTON; OFFICE OF TECHNOLOGY ASSESSMENT, CONGRESS OF THE UNITED STATES Congress of the United States, the legislative branch of the federal government, instituted (1789) by Article 1 of the Constitution of the United States, which prescribes its membership and defines its powers. , 1979; PBS PBS
 in full Public Broadcasting Service

Private, nonprofit U.S. corporation of public television stations. PBS provides its member stations, which are supported by public funds and private contributions rather than by commercials, with educational, cultural,


Cross-Curricular Connection

History: Read about the long-term health consequences of radiation on the populations of Hiroshima and Nagasaki. What happened to citizens when the bombs fell? Five years later? Today?

Did You Know?

* The U.S. has a virtual constellation of early-warning satellites floating 35,406 kilometers (22,000 miles) above Earth.

* A missile interceptor navigates by finding stars that match a "map" stored in its memory chips.

* X-band radar has shorter waves than conventional radar, allowing it to "draw" a clear image of flying objects up to 1,600 kilometers (995 miles) away.

National Science Education Standards The National Science Education Standards (NSES) are a set of guidelines for the science education in primary and secondary schools in the United States, as established by the National Research Council in 1996.  

Grades 5-8: properties and changes of properties in matter * transfer of energy * understanding about science and technology * abilities of technological design

Grades 9-12: atoms * structure and properties of matter * interactions of energy and matter * understanding about science and technology * abilities of technological design


"The Nuclear Shield: Repelling an Attack; A Missile Defense With Limits: The ABC's of the Clinton Plan," The New York New York, state, United States
New York, Middle Atlantic state of the United States. It is bordered by Vermont, Massachusetts, Connecticut, and the Atlantic Ocean (E), New Jersey and Pennsylvania (S), Lakes Erie and Ontario and the Canadian province of
 Times, June 30, 2000.

National Missile Defense Program:

This Boeing site includes many photos and a video clip A short video presentation. : space/nmd/index.html
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Title Annotation:National Missile Defense System; test of National Missile Defense System
Publication:Science World
Geographic Code:1USA
Date:Oct 2, 2000
Previous Article:Sky Show.
Next Article:Can a goldfish live in a can of soda?

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