According to the U.S. Missile Defense Agency, an intercontinental ballistic missile was "successfully intercepted" -- like hitting a bullet with a bullet -- during the first test of its Ground-based Midcourse Defense (GMD) system that targeted a long-range missile.
The ground-based interceptor was launched from the Vandenberg Air Force Base in California while the ICMD-target was launched from Kwajalein Atoll in the Pacific Ocean.
The GMD system is designed to counter a North Korean missile threat and is just one of many components in the U.S.’s larger missile defense system.
In the past, the U.S. has had several canceled programs or abandoned proposals aimed at building up the nation’s missile defense capabilities.
The first successful anti-ballistic missile
The Soviets in 1961 successfully launched an anti-ballistic missile (ABM) that intercepted a ballistic missile. The advancement by the Soviets caused the U.S. to test its own ABM system. In 1972, the U.S. and the Soviet Union signed the Anti-Ballistic Missile Treaty (AMB Treaty), preventing both countries from building up their missile defense systems.
Strategic Defense Initiative - Reagan’s "Star Wars” proposal
“What if free people could live secure in the knowledge that their security did not rest upon the threat of instant U.S. retaliation to deter a Soviet attack, that we could intercept and destroy strategic ballistic missiles before they reached our own soil or that of our allies?” President Reagan said in his March 23, 1983 address to the nation announcing his SDI proposal.
Critics dubbed it “Star Wars,” after the science-fiction movie, because the plan included the development of laser systems in space that would detect and shoot down incoming ballistic missiles.
The SDI was eventually scaled back by Reagan’s successor, George H. W. Bush.
The airborne laser
One idea to shoot down incoming missiles from the sky included strapping lasers to an airplane, dubbed the airborne laser. The concept behind the plane’s development was that the laser would be able to target a ballistic missile while it was in the boost phase shortly after lift-off.
While the Boeing 747 was a no-go, the Pentagon is now envisioning drones with the capability to shoot down ballistic missiles.
In 2002, President George W. Bush withdrew the U.S. from the 1972 Antiballistic Missile Treaty, saying he believed the U.S. should build up its missile defense system in the wake of September 11th.
In 2004, the first GMD interceptors were placed at Fort Greely in Alaska. There are now 32 ground-based interceptors at Fort Greely and four others at Vandenberg Air Force Base in California.
The Missile Defense Agency plans to increase the total number of interceptors to 44 by the end of 2017.