The nation's first operational antisatellite weapon system was brought into being by Space Systems Division during 1963 and 1964. A ground-based system known as Program 437, it employed Thor missiles with nuclear warheads which could be shot into space accurately enough to destroy or disable a hostile space-based weapon or satellite. The Secretary of the Air Force approved the system's development in February 1963. Thor boosters were modified, combined with ground equipment from deactivated Thor missile sites in England, and deployed to Johnston Island in the Pacific. There they were maintained and operated entirely by Air Force military personnel. After four test launches without live warheads--three of them successful--the system was declared fully operational in May 1964, with Air Defense Command as the using command. The capability remained in place, though with few dedicated launchers and a temporary loss of warheads, until 1970.

In 1975, SAMSO began to develop an advanced concept for a follow-on antisatellite weapon system that would not use nuclear warheads. The most promising technology employed a miniature homing vehicle launched into space by a two-stage missile released from an F-15 fighter. The miniature vehicle used a longwave infrared sensor to acquire its target, steered toward the target by selectively firing small rocket motors, and destroyed the target by force of impact. The system was known as the Air-launched ASAT, and it achieved a high degree of technological success. Its first free-flight test took place successfully in January 1984. In September 1985, the ASAT was successfully tested against an orbiting satellite, which it destroyed by impact. Despite further successful tests, the Air-launched ASAT program was terminated by the Air Force in March 1988 because of budgetary constraints and Congressional restrictions.

The air launched antisatellite missile as it is released from its F-15 carrier aircraft and its motor is ignited.