ATK received a contract from Orbital Sciences Corp. to provide first- and second-stage propulsion for the Air Launch Vehicle (ALV) that Orbital is designing and building for Stratolaunch Systems Corp. as part of an air-launched space transportation system. The contract from Orbital includes the design, development, and flight hardware for initial Stratolaunch missions. ATK’s design solution for the ALV will take advantage of the company’s experience with large-diameter solid rocket motors and will use high-strength, low-weight graphite composite cases, advanced propellants, and heritage materials from ATK's line of commercial solid rocket motors. The ALV is made up of three primary elements: a carrier aircraft that is being designed by Scaled Composites, a multi-stage rocket system that is being developed by Orbital, and a payload to be delivered into orbit. Initial efforts will focus on unmanned payloads, with human flights following as safety, reliability, and operability are demonstrated.