A Review of Lunar Regolith Excavation Robotic Device Prototypes

The excavation of lunar regolith is desirable for use as a feedstock for oxygen production processes as well as civil engineering purposes and for the fabrication of parts and structures. This is known as In-Situ Resource Utilization (ISRU). More recently, there has been mounting evidence that water ice exists at the poles of the Moon, buried in the regolith where thermally stable conditions exist. This means that regolith excavation will be required to mine the water ice which is believed to be. mixed in with the regolith, or bonded to it. The mined water ice can then be electrolyzed to produce hydrogen and oxygen propellants which could form the basis of a cis-lunar transportation system using in-situ derived propellants. In 2007, the National Aeronautics & Space Administration (NASA) sponsored a Lunar Regolith Excavation Competition as part of its Centennial Challenges program, The competition was not won and it was held again in 2008 and 2009, when it was won by a university team. A $500,000 prize was awarded to the winning team by NASA. In 2010, NASA continued the competition as a spinoff of the Centennial Challenges, which is restricted to university participation only. This competition is known as the "Lunabotics Mining Competition" and is hosted by NASA at Kennedy Space Center. Twenty three American university teams competed in the 2010 Lunabotics Mining Competition. The competition was held again in May 2011 with over 60 teams registered, including international participation. The competition will be held again in May 2012 at Kennedy Space Center in Florida. . This paper contains a thorough review of the various regolith eX,cavation robotic device prototypes that competed in these NASA competitions, and will. classify the machines and their methods of excavation to document the variety of ideas that were spawned and built to compete at these events. It is hoped that documentation of these robots will serve to help future robotic excavation designers and provide a historical reference for future lunar mining machine endeavors

A Review of Extra-Terrestrial Mining Robot Concepts

Outer space contains a vast amount of resources that offer virtually unlimited wealth to the humans that can access and use them for commercial purposes. One of the key technologies for harvesting these resources is robotic mining of regolith, minerals, ices and metals. The harsh environment and vast distances create challenges that are handled best by robotic machines working in collaboration with human explorers. Humans will benefit from the resources that will be mined by robots. They will visit outposts and mining camps as required for exploration, commerce and scientific research, but a continuous presence is most likely to be provided by robotic mining machines that are remotely controlled by humans. There have been a variety of extra-terrestrial robotic mining concepts proposed over the last 100 years and this paper will attempt to summarize and review concepts in the public domain (government, industry and academia) to serve as an informational resource for future mining robot developers and operators. The challenges associated with these concepts will be discussed and feasibility will be assessed. Future needs associated with commercial efforts will also be investigated

A cryogenic liquid-mirror telescope on the moon to study the early universe

We have studied the feasibility and scientific potential of zenith observing liquid mirror telescopes having 20 to 100 m diameters located on the moon. They would carry out deep infrared surveys to study the distant universe and follow up discoveries made with the 6 m James Webb Space Telescope (JWST), with more detailed images and spectroscopic studies. They could detect objects 100 times fainter than JWST, observing the first, high-red shift stars in the early universe and their assembly into galaxies. We explored the scientific opportunities, key technologies and optimum location of such telescopes. We have demonstrated critical technologies. For example, the primary mirror would necessitate a high-reflectivity liquid that does not evaporate in the lunar vacuum and remains liquid at less than 100K: We have made a crucial demonstration by successfully coating an ionic liquid that has negligible vapor pressure. We also successfully experimented with a liquid mirror spinning on a superconducting bearing, as will be needed for the cryogenic, vacuum environment of the telescope. We have investigated issues related to lunar locations, concluding that locations within a few km of a pole are ideal for deep sky cover and long integration times. We have located ridges and crater rims within 0.5 degrees of the North Pole that are illuminated for at least some sun angles during lunar winter, providing power and temperature control. We also have identified potential problems, like lunar dust. Issues raised by our preliminary study demand additional in-depth analyses. These issues must be fully examined as part of a scientific debate we hope to start with the present article.Comment: 35 pages, 11 figures. To appear in Astrophysical Journal June 20 200

Field Testing of Simulated Lunar Ice Characterization Using Ground Penetrating Radar Technology

Ground-penetrating radar (GPR) is a powerful geophysical method that can accurately characterize contrasting material boundaries within the subsurface in nearly any environment. Compared to other geophysical methodologies, GPR offers the greatest power output versus mass ratio, making it an excellent mechanism for rover technology. Surface mining exploration rovers can be augmented with GPR technology to scan the lunar subsurface for solid water ice bodies to be used in crucial future space endeavors. GPR allows mapping material interface boundaries such as ice, rocks, or metallic objects. The Moon is expected to contain solid water ice within its perpetually dark craters. Our preliminary research is focused on the first meter of depth within the lunar regolith since that is the initial target for potential ice excavation. It is here that solid water ice is expected to exist but in a currently unknown form. Preliminary testing was done to understanding the strengths and weaknesses of the applicable GPR equipment through experimental ice burial testing at a designated testing site. An experimental testbed containing engineered lunar simulant with approximated environmental lunar conditions is planned to be used to analyze the interactions between electromagnetic radio wave propagation and solid water ice. Testing will be done with multiple GPR devices with 50, 100, 500, and 1,000 MHz antenna frequencies. GPR devices equipped with 1,000 MHz antennas are expected to offer the greatest resolution for the depth of interest. Reflection coefficients and permittivity of materials are the key variables that are being addressed before successful characterization of lunar ice bodies. The collected radargram data will be organized into a dataset to be used as a reference for future mining rover missions equipped with GPR

Identifying and quantifying volatile content and geotechnical properties in the lunar psrs

With increased international interest in returning to the lunar surface and harvesting the water ice in the permanently shaded regions it is clear many uncertainties about the geotechnical properties, type and quantity of volatiles remain. Current state of the art in-situ measurements cannot uniquely determine what volatiles are present while determining geotechnical properties. No volatile release profile database exists currently. As part of the inaugural NASA Lunar Surface Technology Research (LuSTR) program, our approach to use a Percussive Hot Cone Penetrometer (DHCP) in combination with Ground Penetrating Radar (GPR) was selected for funding. The team from Michigan Technological University (MTU) and Honeybee Robotics (HBR) will perform this work in two years from 2021-2023. This paper will describe the progress made over the initial summer testing

Method for Thermal Modeling and Volatile Measurement of Lunar Regolith

The opportunity of in situ resource utilization (ISRU) within lunar permanently shaded regions (PSRs) prompts the need for characterizing sources for excavation. The percussive heated cone penetrometer (PHCP) is an instrument being developed, through a Lunar Surface Technology Research (LuSTR) grant at Michigan Technological University (MTU) in the Planetary Surface Technology Development Lab (PSTDL), which will be able to determine the distribution of water-bearing regolith and other volatiles in PSRs. This paper explains the methodology and preliminary results of thermal profiling as well as the development of a thermal model for the PHCP that can identify the presence of volatiles in the surrounding terrain. The evaporation of various volatiles can be detected by recording the temperature as a function of time of the material surrounding the hot penetrometer and comparing the results to a dry reference material. An initial reference test setup with dry F-80 silica sand was used to determine the size of the heat-affected zone at various power levels. In two additional test series, water was then added to these sand samples to account to provide moisture levels of 5% and 10% water by weight. Temperature curves obtained from wet sand samples show plateaus due to the latent heat of vaporization, indicating the presence of water. Tests with dry, wet, and frozen lunar regolith simulant samples were then performed to refine the PHCP thermal model to provide a closer resemblance to lunar material thermal behavior. The data sets from the thermal mapping and modeling will inform the design and manufacturing of the cone penetrometer for the LuSTR project

RedWater: Approach for mining water from Mars’ ice deposits buried 10s of meters deep

Here we present a method for drilling down 10s of meters into Mars subsurface and mining water for In Situ Resource Utilisation

The Snow Badger Mission Concept: Trenching for Ice with Humans and Robots

Snow Badger is a proposed investigation where Artemis astronauts work together with autonomous RASSOR excavation robots to dig trenches near the Artemis landing site to study water ice and other volatiles

RedWater: A Rodwell System to Extract Water from Martian Ice Deposits

The ability to mine ice water in situ is of vital importance to enable future manned exploration of the solar system. In the past decade, orbital measurements have revealed that a third of the Martian surface contains shallow ground ice. Mars reconnaissance orbiter (MRO) shallow subsurface radar (SHARAD) data indicates the presence of debris-covered glaciers as well as buried ice sheets in the Arcadia Planitia (30°N–45°N) that are up to 170 m thick, consist of nearly pure ice, and are covered by at most 20 m of overburden. This data supports the implementation of two proven terrestrial technologies—coiled tube (CT) drilling and a Rodriguez well (RodWell)—for drilling and water extraction on Mars. Honeybee’s RedWater system combines these two technologies into one by first using a CT drilling approach to create a hole, and then, once the hole is made to depth, using the coiled tubing left in the hole as a conduit for water extraction. Models for system performance in this mode have been refined from a combination of U.S. Army Cold Regions Research and Engineering Laboratory (CRREL) research, data collected from Antarctic RodWells, and Honeybee testing. Honeybee plans to validate RedWater’s mechanism designs and extraction models through thermal-vacuum testing to TRL5 in 2020