Explorers 24 and 25
On November 21st 1964 NASA successfully places in orbit two satellites by means of the same launch rocket for the first time. In this case a Scout launcher. Designated Explorers 24 and 25 the craft are a 12 feet balloon and a 2 feet diameter magnetic/radiation investigation satellite respectively.
The prime purpose of Explorer 24 was basically the same as the Beacon satellites of 1959 and 1960 and to provide data on atmospheric drag.