Softgoods Habitats Employing Layered or Trapped Unrefined Regolith Shielding (SHELTURS)

This subtopic addresses and develops technologies that directly support risk reduction and enhancement of deployable softgoods habitats and other crewed inflatable structures. Inflatable habitats provide significant volume reduction for launch and landing through an atmosphere (such as Mars) yet can provide larger deployed volumes once in use versus heritage rigid pressure vessels. This is an area of current high interest to NASA and our industry partners, who are developing crewed inflatables for both in-space and surface habitation applications. Multiple NASA programs, including Artemis, NextSTEP (Appendix A: Habitation and Appendix R: Lunar Logistics and Mobility), Commercial LEO Destinations (CLD), and the Second Collaborations for Commercial Space Capabilities Opportunities (CCSC2), are engaged with industry on maturing and certifying these structures. In addition to volumetric efficiency, there is potential for inflatables to further reduce the required mass to the surface of the Moon and Mars by utilizing in-situ regolith as a means to protect the core structure from the environment and provide additional radiation shielding required for long duration missions. Hybrid surface habitats have been conceptualized that use softgoods for the pressure barrier and structural layers, in combination with piled or bagged regolith for environmental and radiation shielding. Regolith at depths of 2-3m can provide micrometeorite shielding, insulation from the thermal environment, and significant protection from long-term radiation exposure to the crew. Several concepts have been demonstrated for utilizing regolith including: sieving, adding binders, creating feed-stock for large-scale 3D printing, and sintering regolith into bricks or other rigid structure; however, they all require significant and specialized additional hardware and resources to be landed. The combination of regolith with inflatable structures enables use of the indigenous material in its original, raw form, without further processing or beneficiation, and has a clear mission benefit. The focus of this subtopic is specifically on the development of novel approaches to combining the benefits of deployable, inflatable softgoods habitation with in-situ resource use of raw, unprocessed regolith to replace or augment the typical MMOD, thermal, and radiation layers. Using raw regolith minimizes the need for additional resources, energy, time and complexity of processing and allows for potential near-term testing and infusion to extend lunar surface missions. Some of the possible approaches include bagging, compressing, stacking, and leveraging softgoods to aid in encapsulation/securement. Deployable habitats also provide a means to aid in lifting these layers into place as part of their deployment on the surface. This hybrid approach could potentially minimize the required volume and mass of surface habitats and establish early beneficial usage of in-situ resources before more extensive processing capabilities become available possibly in later missions. Parameters of Primary Concern: Approaches minimize the requirements on other surface assets, such as robotic bulldozers, processing plants, large surface power assets etc., to provide regolith and place where needed. Uses only raw, unprocessed regolith. (i.e. collected directly from the surface, without the need for binders, sintering, or other external resources.) Utilizes deployable softgoods structure as the primary crewed volume and takes advantage of the deployment if needed to help raise / place the regolith over its surface. Minimizes the amount of required regolith to encapsulate the habitat and creates a consistent and stabilized layer of regolith of 2-3m depth over the surface of the habitat. More regolith could be placed for instance nearer the base, but analysis of the additional inefficiency and impact on other surface assets and time of construction should be considered. Provides analysis of amounts/densities of regolith needed to help define requirements on current or future excavation assets. Questions to be addressed: How is the regolith obtained/gathered? How is it stabilized without the use of sintering or binding, e.g. bagged, how is the bag filled, and does it need to be sealed? How is the regolith raised into position on the habitat efficiently? How does it stay attached? How is the habitat protected from the regolith, so the underlying layers aren't damaged? What materials should be used to survive the environment including dust, thermal, MMOD, and radiation? (i.e. what depth of regolith is needed and what does it provide in terms of protection from these environmental factors?)