Atlas-Able

The Atlas-Able was an American expendable launch system derived from the SM-65 Atlas missile. It was a member of the Atlas family of rockets and was used to launch several Pioneer spacecraft towards the Moon. The Atlas-Able was a three-and-a-half-stage rocket, with a stage-and-a-half Atlas missile as the first stage, an Able second stage, and an Altair third stage. The first Atlas-Able used an Atlas C as the first stage, but this exploded during a static fire test. The remaining launches used Atlas D missiles.