The environmental conditions of the Moon require mitigation if a long-term human presence is to be achieved for extended periods of time. Radiation, micrometeoroid impacts, high-velocity debris, and thermal cycling represent threats to crew, equipment, and facilities. For decades, local regolith has been suggested as a candidate material to use in the construction of protective barriers. A thickness of roughly 3 m is sufficient protection from both direct and secondary radiation from cosmic rays and solar protons; this thickness is sufficient to reduce radiation exposure even during solar flares. NASA has previously identified a need for innovations that will support lunar habitats using lightweight structures because the reduction of structural mass translates directly into additional up and down mass capability that would facilitate additional logistics capacity and increased science return for all mission phases. The development of non-pressurized primary structures that have synergy with the development of pressurized structures is also of interest. The use of indigenous or in situ materials is also a well-known and active area of research that could drastically improve the practicality of human exploration beyond low-Earth orbit.
The system provides protection by holding a sufficiently thick (3 m) archshaped shell of local regolith around a central cavity. The regolith is held in shape by an arch-shaped jacket made of strong but deployable material. No regolith processing is required. During the regolith filling process, an inflatable structure under the arch supports the mass of the regolith, but once regolith filling is complete the catenary arch formed by the regolith and the jacket becomes self-supporting and the inflatable can be deflated and removed. When complete, habitat modules and equipment can be moved into the protected cavity under the arch. ARMOR is a near-term system that would provide a reliable and robust lightweight structure technology to support large lunar habitats, drastically lower launch mass, and improve efficient volume use, reducing launch costs.
ARMOR also protects from micrometeorites. The kinetic energy of micrometeorites and other debris will be absorbed first by an external, high-strength blanket held over and slightly away from the ARMOR jacket. The projectile penetrates this outer blanket, but becomes fragmented and loses energy in the process. The remnants of the projectile then impact the exterior of the jacket, and the jacket and regolith absorb the remaining kinetic energy. Facilities placed inside the ARMOR will be protected from direct sunlight, reducing the extreme temperature variations. Infrared radiation from the facility will be reflected by the interior of the ARMOR back onto the facility, reducing heat loss.
This work was done by Dr. Louis R. Giersch of Caltech for NASA’s Jet Propulsion Laboratory. NPO-47686
This Brief includes a Technical Support Package (TSP).
Archway for Radiation and Micrometeorite Occurrence Resistance
(reference NPO-47686) is currently available for download from the TSP library.
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Overview
The document discusses the Archway for Radiation and Micrometeorite Occurrence Resistance (ARMOR), a novel structural concept designed for the long-term protection of humans and equipment in space environments. Developed by NASA's Jet Propulsion Laboratory, ARMOR employs a combination of native regolith and a deployable membrane "jacket" to create a multifunctional structure that serves multiple purposes, including radiation shielding, micrometeoroid impact protection, and thermal management.
The ARMOR system consists of an arch-shaped shell made of regolith, approximately 3 meters thick, which surrounds a central cavity. This shell is supported by a strong, deployable jacket that holds the regolith in place. Once the jacket is filled, it becomes self-supporting, allowing for the removal of the inflatable frame. This design enables habitat modules and equipment to be safely moved into the protected area beneath the arch.
Key attributes of the ARMOR system include:
- Multifunctionality: It provides effective radiation and micrometeoroid shielding.
- Cost Efficiency: The design significantly reduces launch mass and improves volume efficiency, leading to lower launch costs.
- Minimal Processing: It requires no significant processing of regolith or existing infrastructure at the construction site.
- Scalability: The system allows for future facility expansion and upgrades.
- Accessibility: It provides external access to the protected facility.
- Sustainability: The structure does not require continuous power or air pressure throughout its operational life.
- Versatility: It can be constructed prior to the arrival of the first human crew or facility module using robotic systems.
The document emphasizes the potential of ARMOR to enhance human presence in space by providing a reliable and efficient means of protection against environmental hazards. It highlights the innovative approach of using local materials and advanced engineering to create a sustainable habitat for future missions. The ARMOR concept represents a significant advancement in aerospace technology, with implications for both scientific research and commercial applications in space exploration.
For further information, the document also provides contact details for the Innovative Technology Assets Management at JPL, indicating the ongoing commitment to research and development in this area.
