Atlas H

The Atlas H was an American expendable launch system derived from the SM-65 Atlas missile and a member of the Atlas family of rockets that Convair built. It was a stage and a half rocket that used the enhanced Atlas first stage designed for the Atlas G, but without that vehicle's Centaur upper stage, and in practice a separate MSD upper stage flew on all five launches. Atlas H flew only from Space Launch Complex 3E at Vandenberg, where it launched five clusters of NOSS ocean surveillance satellites for the US National Reconnaissance Office; two of those flights also carried LiPS satellites as secondary payloads for the United States Naval Research Laboratory. It could put about 3,630 kg into low Earth orbit or about 2,255 kg into geostationary transfer orbit. The same stage was later reused as the first stage of the Atlas I.