The Aegis Ballistic Missile Defense System (Aegis BMD or ABMD), also known as Sea-Based Midcourse, is a United States Department of Defense Missile Defense Agency program developed to provide missile defense against short to intermediate-range ballistic missiles. The program is part of the United States national missile defense strategy and European NATO missile defence system. Aegis BMD is an expansion of the Aegis Combat System deployed on warships, designed to intercept ballistic missiles in post-boost phase and prior to reentry. Aegis BMD-equipped vessels can engage potential threats using the Standard Missile 3 mid-course interceptors and the Standard Missile 2 and Standard Missile 6 terminal-phase interceptors. Notable subcontractors and technical experts include Boeing Defense, Space & Security, Alliant Techsystems (ATK), Honeywell, Engility, Naval Surface Warfare Center, SPAWAR Systems Center, Johns Hopkins University Applied Physics Laboratory (JHU/APL), and the Massachusetts Institute of Technology Lincoln Laboratory (Lincoln Lab). On November 17, 2020, an Aegis Ballistic Missile Defense (BMD) System-equipped destroyer intercepted and destroyed a threat-representative Intercontinental Ballistic Missile (ICBM) target with a Standard Missile-3 (SM-3) Block IIA missile during a flight test demonstration in the broad ocean area northeast of Hawaii. History and technical development Origins The current effort to deploy Aegis ballistic missile defense (ABMD) was begun during the mid-1980s as part of President Ronald Reagan's Strategic Defense Initiative (SDI). The SDI plan was initially for a space-based railgun system. However, technological constraints caused the system to be transformed into a surface-based system known as the Lightweight Exo-Atmospheric Projectile (LEAP). The original testing of the LEAP was done as part of the Army LEAP program. Later, SDIO worked with the Navy to test the LEAP on the Terrier missile. The Terrier LEAP demonstration program lasted from 1991 into 1995 and consisted of four flight tests. Two of these were intercept tests in early 1995; both failed to intercept—the first had a software error in the second-stage booster, the second had a squib (pyrotechnic switch to connect power) in the kinetic kill vehicle that was mounted backwards and failed to fire. Program history and development During the late 1990s, the U.S. Navy was tasked to provide a weapon system for exploratory testing of LEAP. This phase was designated the Aegis LEAP Intercept (ALI) program. The program was for two successful intercepts in five attempts. On June 13, 2002, the second successful ALI intercept occurred during the FM-3 flight test mission. Initial Aegis BMD