Early series of US Earth-orbiting satellites and their associated rocket launcher. Vanguard 1 was the second US satellite, launched on 17 March 1958 by the three-stage Vanguard rocket. Tracking of its orbit revealed that the Earth is slightly pear-shaped. The series ended in September 1959 with Vanguard 3.
The quetzal, the national bird of Guatemala, symbolizes freedom. The blue bands stand for the Caribbean Sea and the Pacific Ocean. The weapons represent the defence of liberty. Effective date: 15 September 1968.