America entered the Space Race on January 31, 1958, when Explorer I was launched into orbit from Pad A of Launch Complex 26 atop a Juno rocket as part of the International Geophysical Year, a worldwide study of the Earth and its environment. Instruments aboard Explorer I discovered the Van Allen radiation belt. Construction of Pad 26A began in 1956, and the Army Ballistic Missile Agency operated it when it became operational in 1957. Before Pad 26A was deactivated in 1963, ten Jupiter, two Redstone, and two Juno launch vehicles were fired from it. Rockets and missiles were placed on a launch stand on a raised steel square at the center of the concrete pad area, and a mobile steel gantry serviced them before launch. A three-foot-deep cableway still connects the pad to the blockhouse that controlled launches, while two sets of water cannons flanked the pad for fire suppression in case of a launch mishap. Several original revetments and support buildings still surround the pad.