Laboratory measurements of RF complex permittivity have been made on a variety of “rocks” encountered in mining, tunneling, and engineering works. An RF impedance bridge and a parallel‐plate capacitance test cell were employed at frequencies of 1, 5, 25, and 100 Mhz. The results predict that low‐loss propagation will be possible in certain granites, limestones, coals, and dry concretes. Existing VHF mining radar equipment should be capable of exploring into such rocks to distances of up to hundreds of feet. Useful but shorter probing distances are predicted for other coals, gypsums, oil shales, dry sandstones, high‐grade tar sands, and schists. Radar probing distances of less than 10 ft are predicted for most shales, clays, and fine‐grained soils. Uncombined moisture content is evidently the, governing factor. Efforts were made throughout the experiments to preserve or simulate the original moisture content of the “rocks” in place.

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Underground cavities (and similar marked lateral changes in seismic impedance) having dimensions of tens to hundreds of meters should markedly reflect artificial seismic waves and locally obstruct reflections from deeper horizons. This should be especially true for liquid‐filled cavities if shear waves are employed. Attempts have been made to apply these principles in delineating solution‐mined cavities in bedded salt. In one seismically reverberant area, results from a brine‐filled cavity 300 m below the surface were unclear. Strong seismic “shadows” were found, however, in a seismic reflection survey of solution cavities 500 m below the surface, in a seismically favorable area. At present, the method requires good reflecting horizons both above and below the stratum to be explored. The amplitude ratio of the two reflections is used to represent the seismic “opacity” of the stratum between, normalized for the effect of varying seismic efficiencies at the shots and detectors. Among other applications, the method should be useful in mapping natural caverns and nuclear‐blast cavities.

This study explores the Design Reference Mission (DRM) architecture developed by Hufenbach et al. (2015) as a prelude to the release of the 2018 Global Exploration Roadmap (GER) developed by the International Space Exploration Coordination Group (ISECG). The focus of this study is the exploration of the south polar region of the Moon, a region that has not been visited by any human missions, yet exhibits a multitude of scientifically important locations-the investigation of which will address long standing questions in lunar research. This DRM architecture involves five landing sites (Malapert massif, South Pole /Shackleton crater, Schrödinger basin, Antoniadi crater, and the South Pole-Aitken basin center), to be visited in sequential years by crew, beginning in 2028. Two Lunar Electric Rovers (LER) are proposed to be tele-robotically operated between sites to rendezvous with crew at the time of the next landing. With engineering parameters in mind we explore the feasibility of tele-robotic operation of these LERs between lunar landing sites, and identify potential high interest sampling locations en-route. Additionally, in-depth sample collection and return traverses are identified for each individual landing site across key geologic terrains that also detail crew Extra-Vehicular Activity (EVA). Exploration at and between landing sites is designed to address a suite of National Research Council (National Research Council, 2007) scientific concepts.

RF losses at 100 Mc/s in artificial samples of salty ice and frozen, fresh‐water‐saturated earths were measured in the laboratory, and pronounced attenuation of radio waves within distances of a few meters are predicted as a general rule. Salty ice dielectric constants averaged 3.5, and resistivities ‘across the grain’ varied from about 55 ohm‐meters at −10°C to about 1200 ohm meters at −40°C for ice containing about 5% of salts. These results may or may not apply to natural sea ice and permafrost.