Burner II was a launch vehicle upper stage developed by Boeing for the Air Force Space Systems Division. It was the first solid-fuel upper stage with full control and guidance capability developed for general space applications. Burner II was designed for use with the Thor booster, but was readily adapted for use on the complete range of standard launch vehicles. Its general assignment was to place small- and medium size payloads into orbit. The Burner II motor, guidance system and reaction control system were integrated to provide attitude stability and precise control of flight rate and burnout velocity for orbital injection and earth-escape missions. Boeing had delivered 8 flight vehicles under its original contract. Under terms of a follow-on contract, it built 6 additional flight models. Four Thor-Burner II combinations were launched successfully from Vandenberg Air Force Base, California. The third launch placed 2 unclassified satellites in Earth orbit. A SECOR satellite, built for the U.S. Army Corps of Engineers by the Cubic Corporation, and an Aurora satellite, developed by Rice University for the Office of Naval Research, were placed in circular orbits 3,300 km above the Earth. As integration contractor for the Air Force Space Experiment Support Program (SESP) Office, Boeing designed, built and tested the injection stage, or "payload dispenser," which carried the 2 satellites on top of a standard Burner II stage and placed them in precise orbits. The satellites were mounted on opposite sides of the injection stage, which housed a640 kgf thrust, solid-propellant rocket motor. The Burner II was used as an upper stage by NASA for deep space probes. Prime Contractor: The Boeing Company. Major Subcontractors Thiokol Chemical Corporation (solid rocket motor); Honeywell Inc. (pre-programmed inertial guidance system); Walter Kidde Co. (reaction control system).