Resilience and Performance of Deployable Space Structures Based on a Shape Memory Polymer Bus

Abstract

Abstract We seek to advance the topic of large-scale space structures for low-frequency radio interferometry enabled by self-folding shape memory polymers (SMPs). Large-scale space structures, greater than 1 km in diameter, are necessary to unlock the secrets of the cosmological dark ages. Two important considerations in developing such large structures are their ability to deploy to the desired configuration in space and their resilience to harsh space environments, which include UV radiation, atomic oxygen, and thermal cycling under vacuum. These environments lead to long-term degradation and erosion of even the most resilient materials. Degradation of SMPs in space applications has potential to affect both material properties and shape-memory performance. Although a plethora of materials have been evaluated in space conditions, the coupled effects of simultaneous space environments on the properties and shape memory performance of polymers has not been evaluated sufficiently. In this study, we evaluate the effects of relevant space environments on the thermomechanical properties of candidate SMPs using laboratory-based experiments. Representative SMP samples are subjected to UV-Oxygen for varying durations. The effects of these environments on material properties for various amounts of exposure are evaluated using differential scanning calorimetry and dynamic mechanical analysis. Knowledge gained from this study includes how the shape recovery required for in-space deployment is affected by space environments and the resilience of these structures to long-term space exposure. Through improved understanding of the effects of space environments on SMP properties and performance, we can advance the field of low-cost, lightweight, self-deploying space structures.