The Burner, Burner II, and Burner IIA rocket stages have been used as upper stages of launch vehicles such as the Thor-Burner and Delta since 1965. The Burner 1 stage was also called the Altair stage and was derived from the fourth stage of the Scout launch vehicle. The Burner 2 stage was powered by a Star 37 solid rocket motor.
In September 1965, Air Force Space Systems Division announced the development of a new, low cost upper stage called Burner II. It was intended as the smallest maneuverable upper stage in the Air Force inventory. In June 1967, the first Thor/Burner II vehicle successfully launched a pair of satellites to orbit. In June 1969, the Space and Missile Systems Organization (SAMSO) began development of the Burner IIA configuration which would offer a tandem motor injection capability and almost twice the capability of Burner II. In June 1971, the last of the Burner II missions was launched from Vandenberg by a Thor/Burner II launch vehicle and carried an SESP-1 space environmental satellite.
In addition to use on Delta family rockets, Burner 2 stages have been used on both Atlas and Titan rockets. Atlas E/F vehicles were configured with a Burner II/IIA stage and launched in 1968 and 1972. The first launch failed with the second delivering a radiation research payload for the Space Test Program (P72-1 Radsat) using Burner IIA.
In the mid-1970s Burner II was also studied for use as an upper stage in combination with the Space Shuttle. NASA managers choose other solutions for missions where upper stages were required.