Voyager 2 was launched from Cape Canaveral on August 20 1977, and made its closest approach to Saturn on August 25, 1981; to Uranus on January 24, 1986; and to Neptune on August 25, 1989. The spacecraft was a 10-sided aluminum framework ring about 18 inches (45 cm) high and 70 inches (179 cm) across. The ring contained 10 electronic packaging compartments. Above the ring was a high-gain antenna dish measuring 12 feet (3.7 m) in diameter and capable of transmitting and receiving at two frequencies in the S and X bands. Voyager 2 was powered by three radioisotope thermoelectric generators located on a boom deployed shortly after launch.