Investigating the Use of Miniaturized Electrodynamic Tethers to Enhance the Capabilities of Femtosatellites and other Ultra-small Satellites

摘要

The success of nanospacecraft and the evolution of the millimeter-scale wireless sensors concept (i.e., "SmartDust") have generated interest in smaller spacecraft, both as stand-alone satellites and elements in a swarm or maneuverable fleet. However, so-called flat ChipSats proposed as complete spacecraft fabricated on semiconductor wafers or other larger pico- and femtosatellite, highly integrated architectures have an inherently high area-to-mass ratio, and this can result in a short orbital life in low Earth orbit (LEO) due to atmospheric drag. In this paper, we summarize trade studies in which we investigate the use of a very short (few meters), semi-rigid electrodynamic (ED) tethers for ChipSat and femtosatellite propulsion. The results reveal that an insulated tether, only a few meters long and tens of microns in diameter, can provide milligram to gram-level ChipSats with complete drag cancellation and the ability to change orbit. We build on an earlier trade study and demonstrate that the EDT system is capable of collecting sufficient current and generating the Lorentz force required for propulsion. Interestingly, the capability of maneuvering in a controlled manner represents an opportunity for any constellation of ultra-small satellites to be more of a reconfigurable, maneuverable fleet rather than a swarm.