Lunar surface mechanical properties

Choate, R.; Batterson, S. A.; Christensen, E. M.; Hutton, R. E.; Jaffe, L. D.; Jones, Rebecca H.; Ko, Hon‐Yim; Spencer, R. L.; Sperling, F. B.

doi:10.1029/jb074i025p06149

Cited by 13 publications

(9 citation statements)

References 3 publications

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“…Of equal concern in the application of the Delesse principle to an estimation of the volumetric particle distribution of the lunar regolith is the vertical variation in porosity. Results obtained from studies of the mechanical properties of the lunar surface [Christensen et al, 1968a, b, c;Choate et. al., 1968] suggest that the lunar regolith is more porous in the upper few millimeters than at greater depths.…”

Section: If the Estimates Of Precision Are Correct It Can Be Seen Frmentioning

confidence: 99%

“…In addition, many of the striations in the wall of the trench, attributed by Gault and others to the surface sampler, may have been formed by coarse grains dragged by the surface sampler along the walls. We believe that the walls of the surface-sampler trenches and footpad imprints are relatively smooth because the bulk of the subsurface material is, in fact, very fine-grained (as indicated in Table 7) and is also somewhat compressible [Choate et al, 1968]. Coarse particles, therefore, would tend to be pressed into the fine-grained matrix by the action of the surface sampler and of the spacecraft footpads and thus obscured by the fine-grained material.…”

Section: _< D _< K -•/• (Listed In Table 2) and (2) N -Kd •' For 1 •mentioning

confidence: 99%

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Physical Characteristics of the Lunar Regolith Determined From Surveyor Television Observations

Shoemaker¹,

Morris²

1970

Radio Science

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The new data on the physical characteristics of the lunar surface derived from the Surveyor pictures can be fitted to a simple ballistic model for the origin and development of the lunar regolith. At a given locality, the size-frequency distributions of craters on the lunar surface can be represented by two functions' Small craters follow a steady-state distribution of the form F --,I,c •, where F is the cumulative number of craters with a diameter >_c, c is the diameter of the craters, ,I, and • have the steady-state values ,I, --10 •0'0, and • ----2.00 at all five Surveyor landing sites. Larger craters are represented by the function F --xc x, where x < tz, and x varies from one landing site to another. The solution for c at the intersection of F --xc X with F --,I,c •', designated as c8, is the upper limiting crater diameter for the steady-state distribution. The value of c8 is a function of the age of the surface on which the regolith has formed. The thickness of the lunar regolith may be estimated from a variety of observational data. The estimated thickness of the regolith at a given Surveyor landing site is bracketed by the original depths of (1) the smallest blocky-rimmed craters that cut through the regolith and excavate coherent material beneath, and (2) the largest, sharp, raised-rim craters without blocks that have been excavated wholly within the slightly cohesive material that forms the regolith. Other direct estimates of the thickness of the regolith are the inferred original depth of the largest craters believed to have been formed by drainage of the regolith material into subregolith fissures and, at the Surveyor-7 site, the depth at which the surface sampler instrument encountered coherent material. The thickest regolith was found at the Surveyor-6 site, where it is estimated to be more than 10 meters thick, and the thinnest was found at the Surveyor-7 site, where it is estimated to be 2 to 15 cm thick. Particle counts from sample areas at each of the Surveyor landing sites show an approximately linear relationship between the log of the cumulative particle counts and the log of the particle size. A power function of the form N --KD x (where N is the cumulative number of particles with diameter equal to or larger than D, and D is the diameter of particles) can be fitted to the data at each site. The size-frequency distribution of resolvable fragments at the Surveyor 3, 5, and 6 landing sites was found to be the same, within errors of estimation, but at the Surveyor 1 and 7 sites coarse fragments are more numerous. Considering all five sites, we found a strong inverse correlation between the abundance of coarse blocks and the thickness of the regolith. The coarsest fragments are most abundant at the sites with the thinnest regolith. INTRODUCTION Five Surveyor spacecraft successfully landed on the moon between June 1966 and January 1968 and returned over 87,000 television pictures which have provided important new data on the physical characteristics of the lunar surface. Surveyors 1, 3, 5, and 6 ...

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Section: If the Estimates Of Precision Are Correct It Can Be Seen Frmentioning

confidence: 99%

Section: _< D _< K -•/• (Listed In Table 2) and (2) N -Kd •' For 1 •mentioning

confidence: 99%

Physical Characteristics of the Lunar Regolith Determined From Surveyor Television Observations

Shoemaker¹,

Morris²

1970

Radio Science

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“…Carrier III et al [3] quote a value of (1-7) 9 10 12 m 2 . This value was derived from lab tests with the exhaust gases of the Surveyor lunar landers, and it was found to be consistent with the expected values for fine-grained regolith-like granular material [5]. In the following model calculation, we have used the upper limit j = 7 9 10 12 m 2 .…”

Section: Gas Escape Via the Regolithmentioning

confidence: 85%

Considerations on a suction drill for lunar surface drilling and sampling: I. Feasibility study

2008

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In this paper, we consider a drilling method, which might prove useful both for applications on the Moon and for drilling on Mars, Venus, or other planetary surfaces. It is based on the use of a cold gas flow for pumping fine-grained debris particles out of the borehole, after they have been pulverized by the bore crown. We present a basic design and demonstrate by a hydrodynamic calculation that such a system should work effectively even on an airless body like the Moon, where the driver gas has to be provided from the associated lander or rover, which acts as the bore platform.

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“…The footpads of landed spacecraft can double as de facto penetrometers, and footpad penetration data have been returned from numerous successful soft landings. Examples include, landed spacecraft on the Moon such as the Lunar Surveyor landers (Choate et al, 1968); the Luna landers and Lunokhod rovers (Cherkasov et al, 1967;Kemurdzhian, Gromov and Shvarev, 1978); the Apollo landers (Carrier, Olhoeft and Mendell, 1991), and on Mars, the Viking landers (Moore et al, 1987). Other examples of penetrometers include the arm-mounted devices on the Venera landers on Venus (Surkov et al, 1984), and a small piezoelectric sensor attached to the underside of the Huygens Probe on Titan, an icy moon of Saturn (Zarnecki et al, 2005) When landing on unconsolidated materials, penetrometers can provide information about the surface layer properties such as cohesion and internal angle of friction.…”

Section: Mechanical Properties Inferred From Penetrometer Datamentioning

confidence: 99%

Principles of Drilling and Excavation

Han

Dusseault

Detournay

et al. 2009

Drilling in Extreme Environments

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Predicting the performance of drills requires analytical capabilities that account for the tools characteristics, rock properties and behavior, the temperature, and other parameters. Also, it necessitates understanding the effect of the applied forces, details of the bit, and the interaction with the drilled rock. This chapter covers the principles of drilling and excavation, both analytically and experimentally, and the requirements for optimization of the drilling operation. Physical Properties of Rocks Terrestrial RocksThe vast array of terrestrial rocks can be simplified into a few basic types. One useful classification scheme is to group rocks via their mode of origin, specifically into igneous, sedimentary, and metamorphic rock types. Igneous rocks are those that solidified directly from a molten state, of which basalt is the prime example. Such rocks can be glassy if quickly cooled, or fully crystalline if allowed to cool slowly. Sedimentary rocks, in contrast, are composed of individual mineral or lithic fragments that have been transported and deposited in layers or strata. These strata have been compacted or re-cemented to form a rock-like mass. Finally, metamorphic rocks are igneous or sedimentary rocks that have altered during burial by heat and/or pressure. The original rock fabric, textures, and mineral assemblages are gradually replaced or overprinted as metamorphism progresses.Drilling in Extreme Environments. Edited by Yoseph Bar-Cohen and Kris Zacny Rock response to external loading depends not only on the level of applied loads, but also on rock properties. Based on their functionalities, there are three categories of rock properties often used in the analysis of rock behavior:. Elastic properties such as Youngs modulus, shear modulus, bulk modulus, Poissons ratio, bulk compressibility, and grain or matrix compressibility. They define rock elastic deformation. . Strength properties describing the loading limit a rock could afford and its plastic behavior. There are several strength variables, such as cohesive strength, tensile strength, compressive strength, and internal friction angle. . Transport properties, for example, rock porosity and permeability, describe the ability of fluid to pass through a rock.These properties are essential for any analytical or numerical effort to describe or predict rock mechanical behavior. The reliability of their values is at least as important as the prediction method itself, if not more so. Rock properties from these categories are not independent. Often, it is found that they are related to each other either directly or indirectly. For example, rocks with high strength are likely to have high modulus, low Poissons ratio, and low porosity. In this section, we will first describe each rock property and its connection with others; then, we will briefly discuss the two methods generally applied to determine its value. 2.2.

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Lunar surface mechanical properties

Cited by 13 publications

References 3 publications

Physical Characteristics of the Lunar Regolith Determined From Surveyor Television Observations

Physical Characteristics of the Lunar Regolith Determined From Surveyor Television Observations

Considerations on a suction drill for lunar surface drilling and sampling: I. Feasibility study

Principles of Drilling and Excavation

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