International planetary sunshade concept with a function-integrated and scalable support structure based on coreless filament winding

Abstract

Despite all current efforts, climate change is the greatest challenge of the 21st century. Since existing measures will fail to prevent critical tipping points from being reached, in addition to terrestrial geoengineering methods, efforts are underway to explore new ways to implement space-based geoengineering methods into the short-term construction of a buffer solution - the International Planetary Sunshade (IPSS). The IPSS system reduces solar irradiation mitigating the global mean temperature rise while offering a sustainable energy supply. The developement of the system poses multifaceted challenges only to be mastered by a collaboration of space agencies and private companies, while supported by society. Therefore, tackling the IPSS within international roadmaps is essential to exploit synergies, shorten development time, and promote international cooperation. An evolutionary concept achieves stepwise Earth independence by utilizing lunar resources. The feasibility of the IPSS also depends on the foil’s supporting structure. Therefore, a lightweight manufacturing technology that meets several criteria, such as scalability, adaptivity, material compatibility, full automation, on-orbit manufacturing, in-situ resource utilization, and digital design including function integration, must be adopted. Hence, coreless filament winding (CFW) may be a suitable technology for realizing the demanded mass savings. The prerequisite for the superiority of CFW structures is an application- and material-compliant component and fiber net design. Previous experience with CFW cannot be directly transferred to the IPSS system due to the changed requirements for space application. This paper will present a systematic design concept for the IPSS, initially exploring a CFW support structure by discussing segmentation and modularity, proposing a new connection system, and implementing function integration.

Long-span fiber composite truss made by coreless filament winding for large-scale satellite structural systems demonstrated on a planetary sunshade concept

“…Here, a potentially viable concept envisions an evolutionary, modular, and scalable sunshade design with incremental development stages spanning several decades: In the initial phase, sunshades are launched from Earth utilizing unfolding mechanisms 50 – 53 . Subsequently, in-space manufacturing and assembly (ISMA) technologies 54 must be applied, considering modularity and segmentation of foil support truss structures 48 . In later stages, the sunshade system’s material is increasingly replaced by in-situ resources (lunar materials).…”

“…Since autonomous manufacturing in space is envisioned, the avoidance of manufacturing aids and metallic inserts is prioritized, and the material usage is targeted towards the lower end of the weight per stiffness spectrum. Therefore, the simplest geometric primitive, an equilateral triangle, is chosen as the base shape for the truss 48 . A high mass-specific stiffness requires high-performance materials, and in case of bending, a framework configuration is favorable as it allows for positioning material cross-sections further away from the neutral axis.…”

“…The case study employs winding pins in the form of a sleeve-washer combination with threaded sleeves. However, future applications may utilize clamps 48 as winding anchors, positioned on a tilted plane relative to the truss’s main axis. This configuration would enable angled connections between trusses.…”

“…The generated undirected graph (nodes and segments) is assembled from different www.nature.com/scientificreports/ raw SKO output features. To increase efficiency and redundancy, these trusses may themselves have a sandwich configuration and may also be subdivided along their main axis 48 . In any case, the individual truss segments' load-carrying capacity must reflect the varying cross-sectional characteristics observed in the raw SKO output.…”

“…Furthermore, several case studies have investigated the impact of fabrication deviation 43 , 44 and correlated data across different process domains 45 . Given that load capacity of CFW structures is significantly influenced by point load induction at anchor elements, various anchor configurations have been studied 46 – 48 . The transfer of point loads into fiber composites poses a challenge, mainly due to elevated stress concentrations.…”