Atlas E/F

The Atlas E/F, also called SB-1A, was an American expendable launch system and sounding rocket assembled from the parts of decommissioned SM-65 Atlas E and Atlas F missiles. Its first stage was reused with various solid-propellant upper stages chosen to suit each payload, and it also flew without an upper stage for a series of re-entry vehicle tests. Thirty such flights carried ABRES and BMRS re-entry vehicles between 1965 and 1974. Other configurations launched OV1 research satellites, early GPS satellites with the SGS stage, Parcae naval reconnaissance satellites with a multiple satellite dispenser, weather satellites for the DMSP, NOAA and TIROS programmes with a Star-37 stage, and Stacksat spacecraft in 1990. On one flight, on 27 June 1978, an RM-81 Agena upper stage on a former Atlas F launched the Seasat satellite, which was the final flight of the Atlas-Agena. Payload capacity to low Earth orbit ranged from about 210 kilograms to over 1,000 kilograms depending on the upper stage.