Squanto Terror was the first known serious attempt by the United States Air Force to develop a practical antisatellite capability. The system involved Thor-launched spacecraft carrying nuclear explosives that could knock out enemy spacecraft by direct contact or explosive concussion. They were loosely based on an October 1962 Air Force/Atomic Energy Commission test, codenamed Starfish. The early Squanto terror tests were highly successful, with dummy warheads coming within a mile of their targets. By 1965, after only three tests, the system was declared operational. A total of 16 test launches, all from Johnson Island in the Pacific, were conducted by the time the tests were concluded in 1968. Meanwhile a 1967 treaty was signed that banned nuclear weapons from space, and by 1975 the Johnson Island facility had been put out of service.