Grant: Research Tools and Instruments

The objective of this experimental program is to design and build a ground testbed to simulate microgravity and magnetic field that an electrodynamic tether (EDT) will experience in space. It consists of a Helmholtz cage hosting a 5-DOF air-bearing spacecraft system. The magnetic field inside the cage is controllable to cancel the local Earth's magnetic field and generate a time-varying magnetic field to simulate EDTs in space across Earth's magnetic field. This will allow us to observe the EDT interaction with Earth's magnetic field and validate EDT stability control strategy/law on Earth. The 5-DOF air-bearing spacecraft system consists of a granite table and a 5-DOF air-bearing spacecraft simulator that carries an EDT. The simulator float on the table that fit inside the Helmholtz cage. The testbed is capable of investigating the electrodynamic behaviors of EDTs and their responses to control actions on Earth. This highly focused experimental program will open up a new window to understand the electromagnetic interaction of EDTs, the dynamics of flexible tether in microgravity and the demanding control problems of these highly nonlinear, multi-physics coupled and under-actuated flexible systems. Due to the prohibitive cost for validation/testing in space, the proposed ground testbed will provide a cost-effective testing facility in an emulated space environment in lab and shed light into the complex problems encountered in the dynamic analysis and control law design. This will allow us to discover some fundamental issues that may be overlooked by existing theories in normal conditions. The electrodynamic tether technology has a great potential in space, for instance, the removal of space debris and the electric solar sail for interplanetary exploration. The proposed equipment will train 11 HQP. All HQP will be trained in multiple facets of technologies relating to electromagnetic interaction, multi-body dynamics and control theory, mechanical design, machining and integration, electronic hardware, wireless communication, software programming, data acquisition and processing, design and implementation of a testing procedure evaluating the performance of the system and development of operational procedures. It will provide a space-like environment to train HQP for the development of satellite payloads and instruments. These hands-on experiences and practical skills will also make HQP more competitive in job market.