An Air-Levitated Testbed for Flux Pinning Interactions at the Nanosatellite Scale

Abstract

Magnetic flux pinning interactions have been recently demonstrated as viable mechanisms in modular spacecraft reconfiguration maneuvers. However, in order to develop a robust testing program for interactions, a low-cost testing environment is necessary to simulate the microgravity environment in which this technology will ultimately perform. The FloatCube testbed we have developed to support this effort is built around uniform free-floating test vehicles with a set of planar air bearings that provide two translational and one rotational degree of freedom. The vehicles allow for rapid implementation of new experiments by providing a standard levitating base segment and optional power, communications, and control components to support experimental actuator and sensor arrangements. The system is also designed to support current and future flight missions and microgravity tests by mounting completed nanosatellites or nanosat-sized modules on individual vehicles capable of operating independently or in formation in concert with a computer interface. This paper presents the design and implementation of the FloatCube system, ongoing work with experimental verification, and future work expected to improve the testbed and verify mission hardware. Nomenclature FPI= Flux-Pinned Interface DOF = Degree of Freedom HTSC = High-Temperature Superconductor T C = Critical Temperature

Control Strategies Utilizing the Physics of Flux-Pinned Interfaces for Spacecraft

“…19 By choosing to simulate parameters that are similar to already constructed hardware, future controller validation can easily be moved to a hardware-in-the-loop system employing the RAGNAR module and an air bearing testbed developed in Cornell's Space System Design Studio. 20 The CubeSat module has a mass of approximately 2 kg, and the inertia estimate (obtained from CAD models) is:…”

Flight Validation of a Multi-Degree-of-Freedom Flux-Pinning Spacecraft Model

“…Working at this scale also enabled the usage of a newly developed laboratory testbed designed to allow unconstrained three degree-of-freedom motion of CubeSat-scale modules. 15 The thermal system was also designed to provide a greater traceability-to-flight for an orbital demonstration by utilizing a cryocooler as its primary cooling source. This method of cooling the superconductors is ideal for use on a spacecraft where electric power could be obtained but cryogenic liquid would be impractical.…”

Operational Capabilities of a Six Degrees of Freedom Spacecraft Simulator

“…Systems which are classified as only planar or only rotational are still widely used in on-the-ground testing. Examples of these include a rotational testbed at Georgia Tech which is used for attitude matching experiments and a planar testbed at Cornell University called FloatCube which was created specifically for testing small scale cooperative satellite maneuvers 2,3 . Combination systems can have 5 to 6 degrees of freedom by combining a planar translation stage and a rotational attitude stage.…”