A Multimodule Planar Air Bearing Testbed for CubeSat-Scale Spacecraft

In the past several years, small satellites have taken on an increasingly important role as affordable technology demonstrators and are now being viewed as viable low-cost platforms for traditional spacecraft mission objectives. As such, the CubeSat standard (1 kg in a 10 cm cube) has been widely adopted for university-led development efforts even as it is embraced by traditional spacecraft developers, such as NASA. As CubeSats begin to take on roles traditionally filled by much larger spacecraft, the infrastructure for dynamics and controls testing must also transition to accommodate the different size and cost scaling associated with CubeSats. While air-bearing-based testbeds are commonly used to enable a variety of traditional ground testing and development for spacecraft, few existing designs are suitable for development of CubeSat-scale technologies, particularly involving multibody dynamics. This work describes Cornell University's FloatCube testbed, which provides a planar reduced-friction environment for multibody dynamics and controls technology development for spacecraft less than 6 kg and a 15 cm cube. The multimodule testbed consists of four free-floating air-bearing platforms with on-board gas supplies that allow the platforms to float over a glass surface without external attachments. Each of these platforms, or FloatCubes, can host CubeSat-sized payloads at widely ranging levels of development, from prototype components to full-scale systems. The FloatCube testbed has already hosted several successful experiments, proving its ability to provide an affordable reduced-friction environment to CubeSat-scale projects. This paper provides information on the system design, cost, performance, operating procedures, and applications of this unique, and increasingly relevant, testbed.