- We're pushing forward our highly promising Strategic
Defense Initiative, a security shield that may one day protect
us and our allies from nuclear attack.
NARRATOR: President Reagan's vision for a Space Age missile
shield never made it beyond the realm of video games.
And that's still how people often tend to picture it.
Even in real life, anti-missile systems often sound like
impenetrable forcefields.
REPORTER: The system spotted a missile and quickly fired.
- 42 scuds engaged, 41 intercepted.
- A 90% success rate in neutralizing the missile
threat.
NARRATOR: But the reality is that intercepting a supersonic
ballistic missile hurling through the sky is anything
but simple, let alone foolproof.
For starters, how far and how fast a missile can go varies
widely.
There's short range, medium range, intermediate range,
then, of course, the Intercontinental Ballistic
Missile, or ICBM.
All of them go through multiple stages of flight.
First is the boost phase.
That's followed by the midcourse phase and the final descent
before detonation, the terminal phase.
To take out a ballistic missile, you need sensors that can track
the incoming warheads and launchers that fire
interceptors-- special missiles that can destroy warheads
simply by colliding into them.
But not all missile defense is created equal.
The US uses two different categories to counter North
Korea.
There's theater defense, and there's homeland defense.
Theater defense is regional.
It includes the anti-missile systems in places like South
Korea, Japan, and Guam that shield American troops
and allies from short and medium-range missiles.
For example, US bases across the region are armed with a Patriot
PAC-3, which intercepts tactical warheads at close range just
before impact.
There are also 19 US warships in the Pacific mounted with Aegis
naval defense radar and launchers.
The ships can fire SM3 interceptors into space to take
out warheads in the midcourse phase of flight.
And there are high-tech truck-mounted launchers in Guam
and South Korea, part of the Terminal High Altitude Area
of Defense, or THAAD.
Designed to be agile and mobile, each truck launcher carries
eight interceptors capable of destroying missiles 125 miles
away, inside or outside the atmosphere.
Experts say that the theater defense systems are not likely
to intercept every missile in a real life attack,
but they've fared well in field tests.
It's an entirely different story when it comes to homeland
defense.
The system protecting the continental US is called
Ground-Based Midcourse Defense.
It has between 36 and 44 interceptors in Alaska
and California, and so far, a track record that might keep
you up at night.
In 18 test launches since 1999, target missiles have been hit
only 10 times.
What's the problem?
A tough target.
The system aims to destroy ICBMs,
which fly far higher and faster than lower-range missiles.
Experts say it's like trying to hit a bullet with a bullet--
bullets that may be flying 20 times faster than the speed
of sound, three times higher than the International Space
Station.
The task is further complicated by the flurry of debris
released when the nuclear warhead separates from the rest
of the missile in space.
Differentiating the warhead from the debris in the threat cloud
is difficult. Experts say even a rising nuclear power,
like North Korea, is capable of using simple decoys or multiple
missiles to confuse the sensors.
And this system is not even designed to defend against
advanced ICBMs from China or Russia.
Ground-based Midcourse Defense is far from a magic shield.
But right now, it's the only system protecting the US.
For more infomation >> 10 TIPS FOR A FIRST-TIME VEGAN + Give Away - 30 Days Being Vegan #3 | CHALLENGE - Duration: 11:43. 
For more infomation >> Why Houston wasnt ready for a big hurricane like Harvey MSNBC - Duration: 3:40. 
For more infomation >> Victoria season 2 spoiler: No happy ending for THIS character as star reveals lonely fate - Duration: 2:42. 
For more infomation >> Sites revealed for new high school ahead of $109 million bond vote - Duration: 2:13. 
For more infomation >> Nutsac Satchel - Stylish gadget bag for men - Duration: 2:25. 
Không có nhận xét nào:
Đăng nhận xét