How Does a Ballistic Missile Work?

Ballistic missile refers to a missile that flies according to a predetermined procedure under the thrust of a rocket engine, and then flies on the trajectory of a free throw object after shutting down. Its flight trajectory is generally divided into active and passive segments: the active segment (also known as the power flight segment or boost segment) is the flight path of the missile from the launch point to the shutdown of the rocket engine under the action of the thrust and guidance system of the rocket engine; The passive section includes the free flight section and the reentry section. It is the path where the missile inertia flies at the given speed and ballistic instrument angle obtained at the end of the active section to the warhead detonation. ^[1]

Missiles usually consist of a warhead, a body structure, a power unit, and a guidance system: ^[2]

There are many ways to classify ballistic missiles: ^[3]

The missile launching method refers to a launching scheme composed of a missile's launching base, launching power, launching attitude, and launching device. In military applications, it is also called a missile deployment method, such as mobile deployment or fixed deployment, which is the result of the integration of the three elements of missile launch location, launch status, and launch power. There are various launch methods of ballistic missiles: 1) According to the launch point, it can be divided into land-based launch and sea-based launch. 2) According to launch power, it can be divided into hot launch and cold launch. 3) According to the launch attitude, it can be divided into tilt launch and vertical launch. 4) According to whether the launching device can be maneuvered, it can be divided into fixed launch and mobile launch. ^[5]

The main characteristics of ballistic missiles are:

1) The missile flies along a predetermined trajectory, attacking fixed targets on the ground.

2) Normally, the vertical launch method is adopted to make the missile take off and rise smoothly, which can shorten the flight distance in the atmosphere, and overcome the air resistance and gravity that act on the missile with minimal energy loss.

3) Most of the missile's trajectories are in a thin atmosphere or in the outer atmosphere. Therefore, it uses a rocket engine, which carries oxidants and burners, and does not rely on oxygen in the atmosphere to assist combustion.

4) The rocket engine has a large thrust and can be used in series and parallel. It can throw heavier warheads to a longer distance.

5) The correction of missile flight attitude is realized by changing the thrust direction.

6) The connection between the various levels of the projectile and between the warhead and the projectile usually adopts a separate structure. When the rocket engine completes the propulsion task, it is thrown away, and only the warhead is directed to the target.

7) When the warhead reenters the atmosphere, strong aerodynamic heating is generated, so heat protection measures need to be taken.

8) Missiles have no wing, no or only small tail, takeoff mass and volume, and complex structure.

9) In order to improve the ability to penetrate and attack multiple targets, strategic ballistic missiles can carry multiple warheads (cluster-type multiple warheads or sub-guided multiple warheads) and penetration devices.

10) Some ballistic missile warheads also have a terminal guidance system, which is used for maneuvering to accurately attack the target. ^[3]

According to the role of the guidance system in the entire flight of the missile, it can be divided into three categories: initial guidance, intermediate guidance and unguided:

1) Initial guidance is mainly used in the initial stage of the trajectory. When the missile is transferred from launch to takeoff and cruise flight, it is guaranteed to enter the predetermined airspace;

2) The role of Chinese guidance is to maintain the correct course and attitude of the missile in the middle of the flight trajectory;

3) Unguided is used for flight segment trajectory to ensure that the missile hits the target accurately. ^[7]

The core ballistic missile defense plan administered by the United States Department of Defense Ballistic Missile Defense Organization (BMDO) is the cornerstone of the theater ballistic missile defense (TBMD) system. It mainly includes Patriot PAC-3, Navy Area Theater Ballistic Missile Defense (TBMD), and high-altitude areas in the theater. Defense (THAAD, or Thaad) and the Navy's total theater defense system. ^[8]

PAC-3 Ballistic Missile Patriot PAC-3 System

PAC-3 is the latest model of the Patriot system. The Patriot System is known for its outstanding performance in the Gulf War. The PAC-3 system will be fully upgraded to a low-level ballistic missile defense (BMD) system in 2001. Its mission is to provide protection for troops and fixed facilities against short- and medium-range ballistic missiles, cruise missiles, and fixed- or rotary-wing aircraft. attack. By design, PAC-3 is required to be easily deployed around the world and transportable by C-17 or C-5 aircraft.

PAC-3 consists of 3 configurations, all of which are upgraded products. To provide troops with missile defense as soon as possible, two original configurations were deployed between 1995 and 1996. The third configuration was deployed in 2001. The final configuration will all use modified system components. The upgraded ground radar has improved its multifunctional, low-altitude, threat detection and identification capabilities. After the target enters the earth's atmosphere, the new PAC-3 missile destroys it by violent impact. This is the so-called dense atmospheric impact killing and intercepting. PAC-3's command, control, and communication systems have been improved over earlier products, and interoperability has been greatly improved. The launching device of PAC-3 is mainly composed of ground radar equipment, interception control station and 8 missile launching equipment. ^[8]

Ballistic missile naval area theater ballistic missile defense system

The U.S. Navy's Aegis cruisers and destroyers are the backbone of the U.S. fleet, and its naval regional theater ballistic missile defense system is based on this. These ships can perform ballistic missile defense missions with only minor improvements. Improvements include upgrades to the ship's AN / SPY-1 radar, Aegis combat system computers and computer programs. The SM-2 BLOCK 4 missile will optimize its anti-cruise and ballistic missile performance, including the addition of an infrared seeker to improve interception accuracy. After this series of improvements, theater commanders have increased their ability to defend against near- and medium-range theater ballistic missiles (TBMs) that reenter the atmosphere. Aegis cruisers and destroyers undertaking theater missile defense system tasks do not require additional personnel. The Navy already has training and logistics infrastructure on site. ^[8]

The sea-based theater missile defense system has several advantages: it can be stationed in the waters near potential crisis "hot spots" where land-based theater missile defense systems are not easy to deploy; ships equipped with naval regional theater ballistic missile defense systems can operate in international waters, so the system Deployment does not require security approval from foreign governments; carrier-based theater missile defense systems can significantly reduce air and marine equipment. ^[8]

Ballistic missile sade system

The Thaad system is the ground-based high-level defense part of the THAAD theater missile defense system. It has a higher interception height and a longer distance than the low-level system, and can strike and kill and intercept both in the atmosphere and outside the atmosphere. Due to the long interception distance, in most cases, sufficient combat space can be guaranteed to intercept the target.

At the same time, the success of the interception can be assessed, and if necessary, a second missile can be launched. Thaad can almost block the entire range of theater ballistic missile threats. The long-range interception can minimize the damage effect of the massively destructive warhead on the ground, and the debris after the interception can not be scattered on the army's head. Therefore, Thaad is one of the key components of the theater missile defense system. The Sade system consists of: ground-based X-band radar, Sade launchers, Sade missiles (boosters and anti-aircraft), and BM / C3I (combat management / command, control, communication, and intelligence systems). ^[8]

Ballistic Missile Naval Theater Defense Plan

The Navy's Total Theater Defense Program (NTW) became a core component of the Theater Missile Defense System Program in 1996 and was designated the Predetermined Major Defense Acquisition Program (Pre-MDAP). Like the Navy's regional ballistic missile defense plan, the Navy's Total Theater Defense Plan plan will continue to improve Aegis ships and standard missiles to increase the missile's outer atmosphere interception capabilities in the ascending, middle, and descending stages. It will increase the operational space of Aegis weapon systems to meet the needs of long-range interceptors. ^[8]