Integration of a High Speed Communications System into ESTCube-2

Abstract

ESTCube-2 was a low Earth orbit CubeSat demonstrator that was launched on 9th of October, 2023. One of the main payloads of the satellite was the Earth observation payload, which was capable of producing images of tens of megabytes. Thus the spacecraft required a dedicated high speed communications system to downlink the images. At the beginning of the thesis, an S-band transmitter had been bought by the ESTCube team for this purpose. This thesis presents the integration of the HISPICO transmitter from IQ Spacecom into the ESTCube-2 platform. This integration involved writing low-level embedded device drivers to control the transmitter. The device drivers were written in C, using FreeRTOS on an STM32L4 microcontroller. Furthermore, the application level logic was created for the reception of images from the imaging payload, dividing the received images into RF frames, and adding forward error correction to the frames - a functionality that exists on HISPICO, but the ESTCube team were not given access to. For the ground station, a reception pipeline using a LimeSDR Mini and GNURadio Companion was created. To test the chain of communication, an image of 76.8 kB was transmitted over 318 HISPICO frames and was successfully received.