American officials have responded to North Korea's preparations for a new IRBM (Intermediate Range Ballistic Missile) test by announcing that sufficient anti-missile systems are being sent to Hawaii to deal with any potential North Korea success with their Taepodong 2 missile. Actually, the U.S. already has anti-missile systems in Hawaii (AEGIS SM-3 and THAAD (Terminal High Altitude Area Defense), and it's unlikely that North Korea has a working IRBM that could travel 7,300 kilometers and hit something in Hawaii.
North Korea has been working on Taepodong 2 for over a decade. An earlier model, launched in1998, went about 1,500 kilometers. A 2006 test barely got off the ground before crashing. A test two months ago only went about 3,000 kilometers. The Taepodong 2 being readied for launch now might make it out to 7,000 kilometers or more. But that's unlikely. So it's a good American PR move to point out that Hawaii is being made safe.
The anti-missile system already in Hawaii are some THAAD systems at the Pacific Missile Range Facility. Last year, the U.S. Army began forming the first of four THAAD batteries. This unit will be ready for combat next year. The other three batteries will be in service within four years. Two years ago, there was a successful test of THAAD (a SCUD type target was destroyed in flight) using a crew of soldiers for the first time, and not manufacturer technicians, to operate the system.
Each THAAD battery will have 24 missiles, three launchers and a fire control communications system. This will include an X-Band radar. The gear for each battery will cost $310 million. The 18 foot long THAAD missiles weigh 1,400 pounds. The range of THAAD is 200 kilometers, max altitude is 150 kilometers, and it is intended for short (like SCUD) or medium range (up to 2,000 kilometer) range ballistic missiles. Tweaks to the system are supposed to make it capable of handling something like the Taepodong 2. THAAD has been in development for two decades. Ultimately, the army would like to buy at least 18 launchers, 1,400 missiles, and 18 radars.
The navy has also modified its Standard anti-aircraft missile system to take down something like the Taepodong 2. This system, the RIM-161A, also known as the Standard Missile 3 (or SM-3), has a longer range than THAAD (over 500 kilometers) and max altitude of 160 kilometers. The SM 3 missiles cost over three million dollars each. The SM 3 has four stages. The first two stages boost the interceptor out of the atmosphere. The third stage fires twice to boost the interceptor farther beyond the earth's atmosphere. Prior to each motor firing it takes a GPS reading to correct course for approaching the target. The fourth stage is the 20 pound LEAP kill vehicle, which uses infrared sensors to close on the target and ram it. The AEGIS/SM-3 combination has had numerous successful tests, and recently shot down a low orbit satellite.
The SM-3 operates from warships (cruisers and destroyers that have been equipped with the special software that enables the AEGIS radar system to detect and track incoming ballistic missiles.) There are several AEGIS equipped ships either near Hawaii, or close enough to reach the islands in less than a week.