CubeStack Wafer Adapter for CubeSats on Small Launch Vehicles

The CubeSat has progressively evolved from a platform for student projects to become a viable spacecraft configuration utilized by numerous government and commercial organizations. The Poly Picosatellite Orbital Deployer (P-POD), from Cal Poly, San Luis Obispo, is the common dispenser for the 3U (three-CubeSat) configuration, and CubeSats are typically launched from dispensers as tertiary payloads, often attached onto an unused surface of the launch vehicle for deployment after completion of the primary mission. The proliferation of CubeSats throughout the small satellite community gives rise to the requirement for more launch opportunities via the addition of multi-payload adapters, coupled with the development of more capable dispensers having 6U and larger form factors. LoadPath and CSA Engineering, under contract to the Air Force Research Laboratory Space Vehicles Directorate, are developing a multi-payload adapter for CubeSats in support of government and commercial missions. The CubeStack adapter is a 10-inch-tall “wafer” similar to the NanoSat Launch Adapter System (NLAS) adapter developed at NASA Ames. The wafer mounts between the rocket upper stage and its primary payload and accommodates eight 3U dispensers, e.g. P-PODs, four 6U CubeSat dispensers, or other combinations of 3U and 6U dispensers. The modular CubeStack wafer features both 38.81 inch and 24.00 inch primary-spacecraft interfaces and is sized for several launch vehicles including Athena, Minotaur I, Taurus, Pegasus and Falcon 1. CubeStack was developed using requirements derived from launch vehicle specifications, customer needs, and lessons learned from the NLAS adapter fabrication and test. CubeStack features include a small part count, minimized weight, and ease of satellite dispenser integration. The CubeStack is expected to be available in 2012. This paper describes the CubeStack development program and design requirements, presents test and validation plans, and details the spacecraft and launch vehicle interfaces.