SCORE or Signal Communications by Orbiting RElay was the world first purpose built communications satellite. It provided a second test of a communications relay system after the first being provided by Pioneer 1.
The Convair SM-65B Atlas, or Atlas B, also designated X-12 was a prototype of the Atlas missile. First flown on 19 July 1958, the Atlas B was the first version of the Atlas rocket to use the stage and a half design with an operational sustainer engine and jettisonable rocket booster section. Unlike later Atlas models, the Atlas B used explosive bolts to jettison the booster section.
Convair, previously Consolidated Vultee, was an American aircraft manufacturing company that later expanded into rockets and spacecraft. The company was formed in 1943 by the merger of Consolidated Aircraft and Vultee Aircraft. In 1953 it was purchased by General Dynamics, and operated as their Convair Division for most of its corporate history.WIKI