Site Preparation and Bulk Regolith Infrastructure
It is envisioned that some of the first possible lunar infrastructures will be structures composed of bulk regolith and rocks. The intent of this subtopic is to develop lunar civil engineering designs, processes, and technologies that produce such structures, and develop concepts of operations (ConOps) for their construction in the South Polar region of the Moon. This is the lunar equivalent of terrestrial “Earth Works.” Earth-based civil engineering processes and technologies are not adequate for lunar construction, therefore lunar civil engineering technologies must be developed. Specific capabilities of interest are:
- Establishing grade.
- Rock removal.
- Berm building.
- Topography mapping to enable cut/fill operations planning and execution.
- Geotechnical characterization.
- Site preparation autonomous operations.
- Regolith hauling/conveying for distances greater that 1 km.
The desired outcome of this effort is “Regolith Works” (engineered surface features and structures) and the design, prototype, testing, analysis, modeling, and demonstration of prototype equipment. These technologies are sought for scaled lunar construction demonstration missions. The following lunar civil engineered structures are of interest to NASA. Proposers are welcome to suggest other regolith-based infrastructure concepts.
- Bulk regolith-based launch/landing zones designed to minimize risks associated with landing/launching on unprepared surfaces for CLPS (Commercial Lunar Payload Services) and HLS (Human Landing System) vehicles.
- Rocket Plume Surface Interaction (PSI) ejecta and blast protection structures.
- Regolith base and subgrade for supporting hardened launch/landing pads, towers, habitats, and other in situ constructed structures.
- Pathways for improved trafficability.
- Solar Particle Event (SPE) and Galactic Cosmic Ray (GCR) shielding.
- Structures for access to subgrade (e.g., trenches and pits).
- Emplaced regolith overburden on structures and equipment.
- Meteoroid impact protection structures.
- Topographical features for terrain relative guidance for flight and surface vehicles.
- Flat and level operational surfaces for equipment positioning, regularly accessed locations, and dust mitigation applications.
- Sloped regolith ramps for access to challenging locations.
- Utility corridors (e.g., electrical, comm, and fluids).
- Shade structures.
- Elevated operational surfaces.
Exact requirements for the full-scale bulk regolith structures are not yet known. Assumptions should be made with supporting rationale to enable initial designs. Specification of lunar civil engineering design criteria should be provided including geotechnical properties.
Tests and validated models/simulations should be developed to characterize the system and regolith infrastructure performance in its intended environments/applications. For example, effects of ejecta impingement upon proposed PSI ejecta protection structures should be characterized including phenomenon such as erosion or secondary ejecta trajectories.
Development of PSI modeling capabilities is not in scope for this subtopic, but collaboration with ongoing PSI modeling efforts is welcome. Information on PSI characteristics can be obtained in the peer-reviewed literature and public NASA reports in the reference section.
ConOps should be developed to define the sequence of steps to complete construction tasks. The ConOps should begin with the natural lunar surface including hills, valleys, and surface and subsurface rocks, and end with the completed bulk regolith infrastructure verified to meet design criteria. A sequence of all required functions of robotic systems and implements should be defined to achieve the task. References to recommended existing spaceflight or protype hardware should be provided for each function. In cases where hardware does not exist, conceptual implement designs should be proposed and critical functions demonstrated in laboratory environments. Concepts should be appropriate for a CLPS scale demonstration mission on the lunar surface (e.g., 25 kg overall mass, 8 kg budget for implements) and assume that the implements would attach to an existing modular mobility platform with interfaces at the forward and aft position. Mobility platforms are not a focus for this topic. A depiction of the integrated construction system concept should be provided.
Proposers may select one or more systems/structures of interest to develop. Infrastructure designs that maximize risk reduction for the Artemis program will be prioritized. ConOps that show promise for implementation by a single, compact, robotic construction system will rank high. Additionally, concepts that employ high Technology Readiness Level (TRL) implements will be prioritized. NASA is seeking systems that can build bulk regolith infrastructure that can be demonstrated in the near term.
Research institute partnering is anticipated to provide analytical, research, and engineering support to the proposers. Examples may include applying civil engineering principles and planning methods, identification and development of needed standards or specifications for lunar structures and operations, regolith interaction modeling, development of analytical models and simulations for verification of system performance, and methods for the design and prototyping of hardware and associated software.
Expected TRL or TRL Range at completion of the Project: 2 to 5
Primary Technology Taxonomy:
- Level 1 07 Exploration Destination Systems
- Level 2 07.2 Mission Infrastructure, Sustainability, and Supportability
Desired Deliverables of Phase I and Phase II:
Desired Deliverables Description:
Phase I must include the design and test of critical attributes associated with the proposed site preparation technology, operations, and achieved site characteristics. Civil engineered design of bulk regolith infrastructure including associated testing, modeling, and simulations must be included. Phase I must also include a ConOps for constructing the infrastructure and verifying the as-built characteristics meet design criteria. An overall construction system concept must be provided. Phase I proposals should result in at least TRL 4 structures and implements.
Phase II deliverables must include demonstration of construction and characterization of bulk regolith infrastructure. The infrastructure must be constructed using robotic systems and implements. Proof of critical functions of the infrastructure and systems must be demonstrated. Structures and systems must be developed to a minimum of TRL 5. Phase II must also include updates to the bulk regolith infrastructure designs, tests, modeling, and simulation based on Artemis program needs refinement and new information.
State of the Art and Critical Gaps:
While civil engineering and construction are well-established practices on Earth, lunar applications remain at low TRLs. The design requirements and functional capabilities of bulk regolith-based lunar infrastructure are not well defined. To date, very few studies have performed civil engineering designs of bulk regolith infrastructure for lunar surface applications. Tests have been performed on Earth but only for short periods of time and with limited environmental and operational fidelity.
Relevance / Science Traceability:
Construction of bulk regolith infrastructure directly addresses the Space Technology Mission Directorate (STMD) strategic thrust “Land: Increase Access to Planetary Surfaces.” It also addresses the strategic thrust of “Live: Sustainable Living and Working Farther from Earth”
Requirements Development Framework for Lunar In Situ Surface Construction of Infrastructure https://doi.org/10.1061/9780784483374.106
Design of an Excavation Robot: Regolith Advanced Surface Systems Operations Robot (RASSOR) 2.0 https://ntrs.nasa.gov/citations/20210011366
Off Earth Landing and Launch Pad Construction—A Critical Technology for Establishing a Long-Term Presence on Extraterrestrial Surfaces https://doi.org/10.1061/9780784483374.079
Plume Surface Interaction (PSI) https://www.nasa.gov/directorates/spacetech/game_changing_development/projects/PSI
Rocket Plume Interactions for NASA Landing Systems https://ntrs.nasa.gov/api/citations/20200000979/downloads/20200000979.pdf
Gas-Particle Flow Simulations for Martian and Lunar Lander Plume-Surface Interaction Prediction https://doi.org/10.1061/9780784483374.009
Understanding and Mitigating Plume Effects During Powered Descents on the Moon and Mars https://baas.aas.org/pub/2021n4i089?readingCollection=7272e5bb