Early Results from the DISCOVERER Project

Abstract

The use of very low Earth orbits (VLEO), for communications and remote sensing satellites, offers a number of significant payload and platform benefits. Imaging from these altitudes allows higher resolution or smaller optical payloads, whilst radar also benefits from improved link budgets leading to smaller antennas and lower transmission power. Communications payloads also have improved link budgets, reduced latency, and improved frequency reuse factors. Platform benefits include a more benign radiation environment, lower cost per kilogram to launch satellites, and atmospheric drag makes the environment inherently sustainable, simultaneously removing debris objects and ensuring satellites are quickly removed from orbit at the end of their operational lives. However, the impact of drag on satellite and mission operations must also be addressed. The DISCOVERER project, which commenced in 2017, is addressing the following key questions about technologies that would enable the commercially viable and sustained operation of satellites in VLEO: 1. Are there materials or processes which reduce the induced drag on spacecraft surfaces? 2. Are there propulsion methods which use the residual atmospheric gas as a propellant, providing drag compensation whilst removing the lifetime limits caused by carrying a limited amount of propellant? 3. How can we improve our understanding of, and make best use of, the orbital aerodynamics of a space platform and its ability to perform attitude control manoeuvres? 4. And what are the new opportunities that these technologies may bring to the market? This paper provides highlights from the developments made during the DISCOVERER project to date, demonstrating the potential for a new, commercially attractive, class of aerodynamic satellites operating in VLEO.