CubeSat testing of Coulomb drag propulsion

TL;DR

This paper discusses the testing of Coulomb drag propulsion using a CubeSat equipped with a long tether system to measure momentum transfer from plasma streams like solar wind or ionospheric flow.

Contribution

It presents the design and planned testing of a Coulomb drag tether experiment on a CubeSat, including the tether construction and measurement approach.

Findings

Design of a 100 m Coulomb drag tether for CubeSat deployment

Method for measuring Coulomb drag via spin rate monitoring

Preparation for in-orbit testing of Coulomb propulsion techniques

Abstract

In Coulomb drag propulsion, a long high voltage tether or system of tethers gathers momentum from a natural plasma stream such as solar wind or ionospheric plasma ram flow. A positively polarised tether in the solar wind can be used for efficient general-purpose interplanetary propellantless propulsion (the electric solar wind sail or E-sail), whereas a negatively polarised tether in LEO can be used for efficient deorbiting of satellites (the plasma brake). Aalto-1 is a 3-U cubesat to be launched in May 2016. The satellite carries three scientific experiments including 100 m long Coulomb drag tether experiment. The tether is made of four 25 and 50 micrometre diameter aluminium wires that are ultrasonically bonded together every few centimetre intervals. The tether can be charged by an onboard voltage source up to one kilovolt positive and negative. The Coulomb drag is measured by monitoring the spin rate.