Enabling high-mass atmospheric entry vehicles, which could transport payloads such as large robotic systems or even humans to other planets, is key in advancing exploration of the solar system. Currently, the size and mass of entry vehicles (3.9t) are constrained due to launcher payload module dimensions (with diameters of 4.6m), consequently limiting interplanetary missions. This research has focused on the design of a novel rigid mechanically-deployable atmospheric entry vehicle concept – the Hypersonic foldable Aeroshell for THermal protection using ORigami (HATHOR) – that could overcome these limitations, allowing larger payload and aeroshell dimensions (e.g. 4.5m and 16m, respectively, for a human mars mission).
This project has included the development of the geometric framework, deployment simulator, and physical design of HATHOR – an aeroshell with an origami-inspired folding pattern that deploys a set of rigid thermal protection system heat shield panels. These panels consist of both a structural and thermal protection layer that deploy into an appropriate geometry for sufficiently decelerating a spacecraft as it enters a planet’s atmosphere. It is found, through deployment analysis, that successful deployment is affected by the panel thickness, the deployment ratio (ratio of deployed to stowed diameter), and the width of the rigid, non-folding, rib components of the heat shield. Successful deployment is shown for deployment ratios of 2<DR<3.5 and panel thicknesses of up to 0.9% of the deployed diameter. These values are selected based on current deployable aeroshell concepts and thermal and structural performance of the thermal protection system.
To validate these results a 2.65m physical engineering model is designed and constructed, based on the Phoenix 2008 Mars mission. A set of fully parameterised computational models is developed to size the HATHOR engineering model based on deployment, thermal, and structural requirements. A final estimated heat shield mass of 82kg is calculated, which is 14% of the referenced total entry mass. Once the engineering model is constructed, preliminary deployment testing is carried out, showing that the rigid panelled heat shield can repeatably and reliably deploy. Automated retraction is also achieved, which is advantageous for testing deployment without human input. This first phase of research brings HATHOR a step closer to being a new enabling atmospheric entry technology for high-mass interplanetary missions.