4 shields protecting America from ballistic missiles

To deal with different types of ballistic missiles, the US builds four complex missile defense systems from short range to high range.

The US launches an interceptor missile during a defense system test in October 2013. Photo: Defenseone

US ballistic missile defense systems are designed to protect the US mainland, military forces deployed around the world and allies from strategic missile attacks by adversaries, according to Defenseone.

Cold WarThe Pentagon sought to develop ballistic missile technology (BMD) to counter the nuclear threat from the Soviet Union, but by the 21st century, the US had shifted its focus to defending against the threat of attack from North Korea and Iran. Supporters of BMD see it as an important tool in projecting US power and its deterrent value, while critics have expressed skepticism about its reliability and cost.

History

In 1972, faced with exponentially growing Soviet and American arsenals, the two countries signed the Anti-Ballistic Missile (ABM) Treaty to limit the number of missile defense system deployment sites in each country to two.

In the early 1980s, the Reagan administration stepped up research and development of ground- and space-based defense systems and announced the Strategic Defense Initiative (PDF), also known as “Star Wars.” In the following years, the U.S. military successfully tested a non-nuclear interceptor that autonomously sought out and destroyed incoming warheads in the Homing Overlay Experiment.

During the George W. Bush administration, the Pentagonproposed a multi-layered, integrated defense system capable of defeating enemy missiles on a global scale. Early in his first term, President Bush withdrew from the ABM Treaty and directed the Pentagon to establish preliminary missile defense systems. The first ground-based missile interceptor was installed at a military base in Alaska in July 2014.

The US Missile Defense Agency (MDA) is developing a range of systems to increase the chances of neutralizing short-range ballistic missile attacks. These systems are not designed to counter large-scale nuclear attacks from Russia and China. MDA has spent about $100 billion on missile defense since 2002 and plans to spend about $8 billion a year through 2017, about 2% of the Pentagon’s base budget.

Mechanism of action

Based on maximum range, there are four common classifications of ballistic missiles: Short-range missiles under 1,000 km, medium-range missiles from 1,000 to 3,000 km, long-range missiles from 3,000 to 5,000 km, and intercontinental missiles from 5,500 km and above.

Ballistic missiles have three phases of flight: the ascent phase, which begins at launch until the rocket engine runs out of fuel and the missile penetrates the atmosphere; the middle phase, which is the longest phase, when the missile flies in a parabolic trajectory into space, when it reaches maximum altitude the warhead separates and gradually loses altitude; and the final phase, when the warhead re-enters the atmosphere and usually reaches its target in less than a minute (unlike cruise missiles that use jet engines to fly low and level with the ground to avoid radar before attacking the target).

Defeating ballistic missiles requires four mechanisms: detection, discrimination (sorting the missile from other flying objects), fire control to lock on the target (determining the exact point of interception), and destruction (using several interceptors to attack the missile). However, the effectiveness of the BMD system in tests has not shown reliability, leaving many skeptical about its value in real combat conditions.

The US uses a variety of launchers to fire ballistic missiles including bunkers, trucks, trains, submarines and warships, withThe four BMD programs primarily serve as shields to protect the country and its allies from missile threats.

The Ground-Based Midcourse Defense System is the most complex and expensive program in the US missile defense system, designed to destroy medium- and long-range missiles in space.

The US Terminal High Altitude Area Defense (THAAD) missile defense system. Photo: Wikipedia

In 2004, 26 of these interceptors were deployed at Fort Greely, Alaska, and four at Vandenberg Air Force Base, California, with plans to increase that to 44 by 2017. In a June 2014 test, an interceptor launched from Vandenberg destroyed a target missile launched from the Marshall Islands, the first successful intercept in four tests since 2008. In addition, some US officials now support a proposal to build a third interceptor site on the East Coast.

The Aegis Ballistic Missile Defense system is considered the most reliable program of the entire defense system. This sea-based defense system is designed to intercept short- and medium-range ballistic missiles. MDA and the US Navy plan to increase the number of warships equipped with the Aegis system from 33 in 2014 to 43 in 2019. In June 2014, the Pentagon said the system had successfully intercepted 28 out of 34 tests.

The Terminal High Altitude Area Defense (THAAD) system is a rapidly deployable vehicle-based system designed to intercept short- and medium-range ballistic missiles inside and outside the atmosphere. As of mid-2014, there were three THAAD systems in operation, but the Pentagon wants to increase the number to seven.

The Patriot Advanced Capability-3 (PAC-3) missile defense system is the most advanced system in the U.S. missile defense arsenal. It can be deployed quickly because it is mounted on a vehicle and uses sensors to track and intercept missiles in their terminal phase at lower altitudes than the THAAD system. The PAC-3 system was used in the 2013 Iraq war but was not very successful. PAC-3 and its variants have been deployed to South Korea, Afghanistan and more than 10 other countries.

According to VNE