The Terminal High Altitude Area Defense (THAAD) system is a long-range, land-based theater defense weapon that acts as the upper tier of a basic 2-tiered defense against ballistic missiles. It’s designed to intercept missiles during late mid-course or final stage flight, flying at high altitudes within and even outside the atmosphere. This allows it to provide broad area coverage against threats to critical assets such as population centers and industrial resources as well as military forces, hence its previous “theater (of operations) high altitude area defense” designation.
This capability makes THAAD different from a Patriot PAC-3 or the future MEADS system, which are point defense options with limited range that are designed to hit a missile or warhead just before impact. The SM-3 Standard missile is a far better comparison, and land-based SM-3 programs will make it a direct THAAD competitor. So far, both programs remain underway.
The THAAD terminal (formerly theatre) high-altitude area defence missile system is an easily transportable defensive weapon system to protect against hostile incoming threats such as tactical and theatre ballistic missiles at ranges of 200km and at altitudes up to 150km.
The THAAD system provides the upper tier of a ‘layered defensive shield’ to protect high value strategic or tactical sites such as airfields or populations centres. The THAAD missile intercepts exo-atmospheric and endo-atmospheric threats.
THAAD system provides the upper tier of a ‘layered defensive shield’
The sites would also be protected with lower and medium-tier defensive shield systems such as the Patriot PAC-3 which intercepts hostile incoming missiles at 20 to 100 times lower altitudes.
Patriot PAC-3 Air & Missile Defense System protects the lower and medium-tier defensive shield systems
THAAD missile battery
The THAAD battery typically operates nine launch vehicles each carrying eight missiles, with two mobile tactical operations centres (TOCs) and a ground-based radar (GBR).
THAAD missile information
The target object data and the predicted intercept point are downloaded to the missile prior to launch. The updated target and intercept data are also transmitted to the missile in flight.
The missile is 6.17m in length and is equipped with a single stage solid fuel rocket motor with thrust vectoring. The rocket motor is supplied by Pratt & Whitney Rocketdyne. The launch weight is 900kg.
A separation motor is installed at the interstage at the forward end of the booster section. The separation motor assists in the separation of the kinetic kill vehicle (KKV) and the spent boost motor.
The shroud separates from the KV before impact. The KV is equipped with a liquid-fuelled divert and attitude control system (DACS), developed by Pratt & Whitney Rocketdyne, for the terminal maneuvering towards the target intercept point.
A gimbal-mounted infrared seeker module in the nose section provides terminal homing to close in on the target missile in the terminal phase of approach.
During the initial fly-out phase of flight, the seeker window is covered with a two-piece clamshell protection shroud. Metal bladders installed in the shroud are inflated to eject the protective shroud before the seeker initiates target acquisition. The infrared seeker head, developed by BAe Systems, is an indium antimonide (InSb) staring focal plane array operating in the mid infrared 3 to 5 micron wavelength band.
Lockheed Working To Extend Range of U.S.Missile Interceptors: HERE
Unlike the current THAAD interceptor, which uses a single-stage rocket, the longer-range version would have two stages, similar to rockets that launch satellites into orbit. The first rocket would launch the interceptor to a high altitude in or above the Earth’s atmosphere while a second “kick stage” would propel the rocket toward the enemy missile.
“The first stage gets you out longer and higher against modern threats and the kick stage is responsible for narrowing the distance between the target and the interceptor so you could turn over to the kill vehicle,”
A missile defense system works like this: A missile is launched. Ground and space sensors detect that launch and calculate the speed and path of the missile as it makes its way into space. A rocket-powered interceptor is then launched and put on a collision course with the missile, destroying it before it hits the target.
THAAD is designed to intercept an enemy missile as it re-enters the Earth’s atmosphere.
“By going to the [THAAD extended range] version, where you have a bigger booster and a kick stage, you can launch much earlier and you can attack that threat before he might try to do some evasive maneuvers,”
Image: keypublishing.comImage: keypublishing.com
“With an additional stage and an ability to loiter, THAAD[extended range] has been reported to have nine to 12 times existing THAAD coverage, and its increased velocity could potentially both counter hypersonic threats and have homeland missile defense applications, supplementing [Ground-Based Midcourse Defense],” Excerpt from defenseone.com
Image: keypublishing.comLaunch vehical missile reduced from 8 to 6 missiles to accomodate the larger ER version – Image: keypublishing.com
M1075 truck-mounted launcher
There are nine M1075 truck mounted launchers in a typical THAAD battery. Launch vehicle is a modified Oshkosh Truck Corporation heavy expanded mobility tactical truck with load-handling system (HEMTT-LHS). The 12m-long by 3.25m-wide launch vehicle carries ten missile launch containers. While on the launcher, lead acid batteries provide the primary power. The batteries are recharged with a low-noise generator.
After firing, reloading the launch vehicle takes 30 minutes.
The cueing for the THAAD system is provided by the Raytheon Systems AN/TPY-2 ground-based radar (GBR) for surveillance, threat classification and threat identification. THAAD can also be cued by military surveillance satellites such as Brilliant Eyes.
Raytheon Systems AN/TPY-2 ground-based radar and cooling equipment unitAN/TPY-2 radar
The AN/TPY-2 radar provides a common mission capability:
- in Terminal-Based Mode (TBM) with the THAAD Fire Control Center in support of the THAAD weapon system, and
- in a Forward-Based Mode (FBM) with command, control, battle management and communications, enabling MDA’s Ballistic Missile Defense System.
Antenna Equipment – Image @upi.com
The electronic equipment unit houses radar control and signal/data processing equipment using modified software to provide acquisition and tracking of ballistic missiles of all ranges in the boost phase and the transition to the midcourse phase of flight. The system uses fibre optic datalinks as the communications medium. The radar and system components require a total of 2.1 megawatts of power to operate.
The AN/TPY-2 radar system elements include:
- the phased-array antenna
- the electronic equipment unit
- a 1.1 MW prime power unit
- a cooling equipment unit which provides cooling for the antenna array
- an operator control unit which contains operator consoles for operations, maintenance and communications monitoring (using an own power unit).
Cooling Equipment Unit – Image: globalsecurity.org
The ground based radar units are C-130 air transportable. The AN/TPY-2 radar uses a 9.2m² aperture full field of view antenna phased array operating at I and J bands (X band) and containing 25,344 solid-state microwave transmit and receive modules. The radar has the capability to acquire missile threats at ranges up to 1,000km.
The first production radar is being tested at the White Sands Missile Range in New Mexico. In September 2004, the THAAD radar tracked a tactical ballistic missile, cueing a successful intercept by a Patriot PAC-3 missile. A second radar was delivered to White Sands in June 2007.
Tactical operations centre
Image: mda.milImage: mda.mil
Each THAAD battery has two tactical operations centres (TOC). The TOC has been developed by Northrop Grumman, formerly Litton Data Systems Division. The TOC accommodates two operator stations and is equipped with three Hewlett-Packard HP-735 data processors.
Interior View of TFCC Tactical Operations Station (TOS) – Image: globalsecurity.org
Mobile BMC3I units
The THAAD system is able to ‘hand over’ targets to other defence systems and can cue the targets to other weapons. THAAD is able to interface to other US or allied air defence data information networks and to the battle management and command control and communications centre.
Northrop Grumman has been contracted to develop the THAAD BMC3I. The battle management and command, control, computers and intelligence (BMC3I) units are installed in hardened shelters mounted on high-mobility multi-wheeled vehicles (HMMWVs).
The THAAD communications system can use JTIDS, mobile subscriber equipment, SINCGARS and the joint tactical terminal for voice and data communications and for intelligence data transfer.
Source: fas.org/radartutorial.eu/army-technology.com/ mda.mil/lockheedmartin.comps
Updated Oct 18, 2016