ESTCube-1 Tether End Mass Imaging System Design and Assembly

Abstract

The primary mission of the first Estonian student satellite, ESTCube-1, is to test the electric solar wind sail principle in ionospheric plasma. In order to accomplish this, the CubeSat standard based spacecraft will be launched into polar low-Earth orbit (LEO) and a small aluminium mass attached to the end of a 10 m long tether is to be reeled out using centrifugal force. The tether is then charged and the effect of ionospheric plasma on the angular velocity of the satellite is measured. During this experiment, the deployment of the tether needs to be verified. Therefore, an imaging system capable of capturing the tether end mass at various distances from the satellite has been developed. On ESTCube-1 this system is also used to carry out the secondary objective of Earth imaging for outreach purposes. Moreover, the camera has been designed as an independent module that is reusable in future spacecraft missions with extremely limited weight, volume, power, and communication bandwidth. The goals of this work were stated as follows: • List the requirements for the camera subsystem of ESTCube-1. • Design an independent, robust, and reusable camera module for use in small satellites. • Outline camera module firmware design. • Create software for camera control and testing. • Test the functionality and electrical characteristics of the resulting hardware. The research presented in this study was conducted over a period of one and a half years. During this time preliminary studies were conducted, two hardware prototypes and the final engineering model were constructed and tested. Several iterations of firmware and detailed test plans were developed.