Lean satellite design for amateur communications payload in the ESA ESEO mission

AMSAT-UK and the Surrey Space Centre are cooperating in delivering an educational communication payload for the ESA European Student Earth Orbiter (ESEO) mission, comprising a payload computer, an L-band receiver and a VHF transmitter. The primary purpose of the payload is to provide downlink telemetry that can be easily received by schools and colleges for educational outreach purposes [1]. Common space industry standards such as European Cooperation for Space Standardization (ECSS) consist of a large number of documents that were primarily written for large-scale space missions. Academic space projects cannot follow these design guidelines due to a lack of sufficient expertise, human resources, facilities or equipment. However, many projects were successfully developed, launched and operated with major deviations from ECSS standards. A recently published CubeSat standard consists of tailored ECSS requirements with the aim to improve the applicability of these specifications to small satellite projects. These, however, are still incompatible with the limited working environment of most university projects. In recent years, a `lean satellite' design approach that utilises non-traditional, risk-taking development and management was proposed by Cho et al. [2] to address these issues. This design approach was successfully applied by the AMSAT project team to develop a proto-flight model of the payload which entailed an improvement of customer specification compliance from 81% to 86% with respect to the engineering model. This method allowed a low cost and fast development process as well as passing all functional and environmental tests without major issues. A key finding was that despite having superior facilities, equipment and expertise compared to most academic CubeSat teams, only an overall compliance of 82% to the CubeSat standard and 57% to the analysed set of ECSS specifications could be achieved. This shows the challenge small space projects face when following conventional industry specifications such as ECSS which are written for traditional space missions. Following this, it is recommended to further promote the development of a new ISO standard for lean satellite design which could ease the development process and reliability of small space projects that struggle to fully comply to ECSS or CubeSat specifications.