Design of the Alpha CubeSat: Technology Demonstration of a ChipSat-Equipped Retroreflective Light Sail

Abstract: This paper provides an overview of Alpha, a rapidly developed, low-cost CubeSat mission to verify the performance of a highly retroreflective material for light-sail propulsion. Designed, integrated, and tested by students of the Space Systems Design Studio at Cornell University, this mission demonstrates a number of key technologies that enable next-generation capabilities for space exploration. In particular, this paper focuses on the novel application of ChipSats (gram scale spacecraft-on-a-chip technology) as a means of verifying Alpha’s sail orbit and attitude dynamics. Other innovations include an entirely 3D-printed structure to enable quick and inexpensive prototyping, an onboard Iridium modem that bypasses the need for ground-station radio equipment, retroreflective sail material that provides more deterministic thrust from laser illumination, and an attitude-control subsystem that provides full attitude and angular-rate control using magnetorquers only. In addition to these near-term technology demonstrations, Alpha is among the first exhibitions of holography in space, a medium that shows longer-term promise in several roles for interstellar travel.