Description: Objectives: This proposed study would take an innovative approach to designing tailored habitats by utilizing hybrid-composites and novel manufacturing methods to reduce habitat mass and improve affordability over traditional composites, soft goods, and metallic approaches. Composite manufacturing methods (e.g., automated fiber placement, thin-ply composites, sandwichcomposites, stitched composites, textile composites, fiber metal laminates, andother methods providing benefits for different habitat structural features) would be assessed against their desirable structural properties, ease of manufacture, and ability to join efficiently with other composite types. Hybrid-composite habitat configurations would then be generated that advantageously apply these manufacturing methods to structural features of the habitat including large sections of uninterrupted habitat shell (i.e., acreage), areas with hatch or window cutouts (i.e., discontinuities), hatches, and secondary structure such as ring frames and stringers. Promising combinations of manufacturing methods would be applied to conceptual Deep SpaceTransport and lunar surface ascent cabin habitat designs which would beassessed on 1) lowering mass ... (with a target of 20% reduction in structural mass over traditional aluminum manufacturing), 2) improving (or maintaining) performance to reduce risk and extend life, and 3) improving manufacturing and processing to reduce costs (and improve joining). \n \nThe goal of this study would be to mature the concept of hybrid-composite habitat structures to enable a successful Game Changing proposal in Spring FY19 by 1) identifying advantageous composites combinations for demonstration in follow-on component, sub-scale, and full-scale habitat hardware tests, and 2) identifying knowledge gaps for particular composite combinations for further research. Additionally, the proposed design method leveraging hybrid-composites paves out a new design paradigm for composites that challenges existing methods and opens new avenues for research across a range ofapplications (e.g., aeronautics, space). This proposal addresses the Langley grand challenges of Safe Travel beyond Low Earth Orbit and Innovative Concepts for Landing 20 Metric Tons on Mars through the reduction of habitat, rover, and surface cabin masses, which represent 5-10 elements in lunar and Mars architectures.\n \nImplementation: The proposal would leverage a detailed Formulation Engineering Design Studio (EDS) session with NASA composites,structures, and habitation Subject Matter Experts to define the design space for the composite methods and map them to the habitat structural features according to their technical strengths and costs. Then the most advantageous combinations of composite methods would be assessed in two stages: 1) a Systems Level Assessment of the potential mass reductions compared to traditional alternatives and 2) a Detailed Composites Design of the most promising combinations. During the detailed design, composite structures experts would characterize and design the interfaces between multiple composite techniques to mitigate joining issues. Furthermore, procurement would be leveraged to develop a Coupon Manufacturing and Test Approach focused on joining composites developed with different techniques. Certification and requirements will be addressed at this stage as well to mitigate future mass growth. Interim and Final Reports characterizing habitat design challenges and advantageous solutions would serve as checkpoints for the team and center leaderships. \n \nThe team would leverage experience in systems analysis, habitation design, structures design, composites manufacturing, and testing to inform this study building upon the lessons learned from the Composite Crew Module project (2007-2011), the Composite Cryotank project (2011-2014), the Advanced Composites Project, non-destructive evaluation advances, and other aeronautics industry composites techniques. Matt Simon of the Space Mission Analysis Branch (E402) will co-lead the study and provide formulation, analysis, and conceptual habitat design for the structural analysis. Wade Jackson of the Durability, Damage Tolerance, & Reliability Branch (D309) will co-lead the study and provide composites expertise, design, and analysis, as well as oversight for the planning and development of small-scale manufacturing demos. The Vehicle Analysis Branch (E401) will provide systems level structural analysis to quickly assess possible techniques and identify those worthy of further analysis. The Engineering Directorate would be asked to assess certification and requirements to ensure designs are suitable for flight. The Marshall Space Flight Center Advanced Concepts Office may alsoprovide habitat and structures design guidance pending management approval. Results will be coordinated with the ongoing Advanced Composites Project and Composites Technology for Exploration Project, which may augment this effort with some composites joining coupon articles synergistic with FY19 project plans. \n\nReferences: \n Kirsch, M., Composite Crew Module: PrimaryStructure, NASA/TM-2011-217185, NESC-RP-06-019, NASA, 2011.\n Belvin, W. K., Watson, J. J., and Singhal, S.N., Structural Concepts and Materials for Lunar Exploration Habitats,AIAA-2006-7338, AIAA SPACE 2006 Conference and Exposition, San Jose, CA, 19-21Sept. 2006.

Benefits:

Background: Habitats for human exploration missions to the Moon and Mars (including rovers and surface ascent cabins) are often massive and high \u2018gear ratio' elements, which must be pushed through many propulsive burns. Small increases in habitat mass can translate into large mass changes in launch vehicles and propulsion stages, which often drive the overall affordability and complexity of a mission. Targeted investment to reduce mass of habitat designs is impactful for the development of any human space exploration mission. Substantial mass reductions can be achieved through the application of technologies to develop lightweight, efficient, optimized structures (see technology roadmaps TA 12.1.1, TA 12.2.1). Studies designing composite structures for habitats have identified the potential performance benefits of composites over traditional aluminum structures to reduce the structural mass of exploration habitats, and these reductions generally constitute significant portions of habitat masses (especially for small pressure vessels such as rovers and ascentcabins). However, the mass savings in these studies are limited by inherited requirements, the application of only a single type of composites material and manufacturing method across a complicated habitat design, and a lack of early considerationof required joints (Example: Composite Crew Module - Ref.1). There is an opportunity to achieve substantial mass savings by implementing a hybrid-composite habitat structure, which applies different, optimal composite materials and manufacturing methods for each part of the habitat structure (e.g., acreage, discontinuities,secondary structure, etc.) customized to its unique structural requirements. This proposed study would take an innovative approach to designing tailored habitats by utilizing hybrid-composites and novel manufacturing methods to reduce habitat mass and improve affordability over traditional composites, soft goods, and metallic approaches. Promising combinations of manufacturing methods would be applied to conceptual Deep Space Transport and lunar surface ascent cabin habitat designs which would be assessed on “1) lowering mass … (with a target of 20% reduction in structural mass over traditional aluminum manufacturing), 2) improving (or maintaining) performance to reduce risk and extend life, and 3) improving manufacturing and processing to reduce costs (and improve joining)”.This proposal addresses the Langley grand challenges of safe travel beyond low Earth orbit and innovative concepts for landing 20 metric tons on Mars through the reduction of habitat, rover, and surface cabin masses, which represent 5-10 elements in lunar and Mars architectures.