Developing a 3U CubeSat Engineering Model - FlatSat & Chassis Design

WUSAT-3 is a 3U CubeSat being designed to carry an experimental RF signal direction finding payload in Low Earth Orbit (LEO). Successful outcome of this experiment could lead to significant benefits for the field of wildlife monitoring from Space. Commercial adoption of this process would enable the development and use of much smaller, lighter RF tracking tags, which in turn would considerably increase the potential range of species that could be tracked by Satellites. The effect of the Covid-19 pandemic lockdowns has limited physical progress over the past 18 months, but the team continues to gain enormous experience and motivation from pursuing this exciting project with a very real-world mission. A recent return to near-normal working patterns has enabled the team to fully engage with the practicalities of progressing the previously produced WUSAT-3 Configuration Model, towards a testable Engineering Model. This paper outlines the development of both the initial chassis prototype (including mechanisms) and a subsystem FlatSat as a first stage towards building the complete Engineering Model. The chassis prototype was required to meet all the requirements of the FYS Design Specification [1], the NanoRacks CubeSat ICD [2], the CubeSat Design Specification [3] and those features identified by the outcomes of the WUSAT-3 Configuration Model. The FlatSat was required to include all subsystems capable of being constructed and tested without the availability of certain proprietary items that will be purchased later. The function and interface of these items, where it was necessary for the purpose of testing the assembled subsystem units that were available, was met by the design and inclusion of temporary substitute arrangements that provided similar performance. Systems Engineering methodologies were employed throughout as a means of ensuring that the design features of both chassis and FlatSat met all necessary requirement