Integrated Design of a Modular Thermoplastic Satellite Bus for Very Low Earth Orbit Applications

Thermoplastic composites remain underutilized as primary satellite bus structures, largely due to the absence of integrated design approaches that, simultaneously, account for material anisotropy, manufacturing constraints, and launcher-driven requirements. This work addresses that gap through the development of a modular thermoplastic satellite bus tailored to the structural drivers of very low Earth orbit (VLEO) missions, including mass efficiency, drag-aware geometry, and end-of-life considerations. Carbon-fibre-reinforced polyether-ether-ketone (PEEK-CF) is selected using a multi-criteria VIKOR decision-making method that considers manufacturability, mechanical performance, thermal stability, and environmental resistance. The structural design is developed in alignment with thermoforming and over-moulding processes and emphasizes modularity and scalability. High-fidelity finite element analyses are conducted to assess quasi-static launch loads, modal behaviour, and random vibration environments, using system-level constraints derived from TRL-9 commercial off-the-shelf (COTS) components. The resulting structure, developed to TRL 3-4, corresponds to an 11 kg microsatellite compliant with the load and frequency requirements of a representative rideshare launcher. The study demonstrates the feasibility of a fully thermoplastic satellite bus through an integrated co-design of material, manufacturing, structural, and mission requirements, with applicability to other small satellite classes.