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All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

Vertical Lunar Regolith Conveying as a Flight Experiment in Simulated Lunar-Gravity

Regolith conveying will be an essential task for supplying regolith feedstock to In-Situ Resource Utilization (ISRU) reactor systems for regolith processing on the Moon and Mars. The Vertical Lunar Regolith Conveyor (VLRC) is a technology being developed at NASA Kennedy Space Center (KSC) as a regolith transport task for the GCD ISRU FLEET project led by NASA Glenn Research Center (GRC). Single test loop versions of the VLRC are being developed at NASA KSC as a technology demonstration for a flight experiment. The NASA Flight Opportunities program selected the VLRC for a technology demonstration opportunity on a future Blue Origin New Shepard suborbital launch vehicle to study regolith transport physics in a relevant environment in a vacuum chamber under simulated lunar gravity conditions in order to advance its technology readiness level (TRL) for future space applications. The VLRC system includes four primary subsystems to achieve the objectives of the lunar gravity (Lunar-G) flight experiment. (1) An eccentric vibratory conveyor stack to convey regolith particles consisting of three single-loop helical surface conveyors with each actuated by two vibratory motors that vibrate in unison. One of the three single-loops contains a 0.8°-3.1° inclined helical path and the other two contain a 1.6°-6.2° incline. (2) A stick-slip conveyor stack to convey regolith particles consisting of three single-loop helical surface conveyors with each actuated by the same motor to move in unison in a stick-slip motion. One of the three single-loops contains a 0.8°-3.1° inclined helical path and the other two contain a 1.6°-6.2° incline. (3) A regolith containment system to contain the regolith in each single-loop track during launch before the start of the experiment using containment caps that will be lifted in unison at the start of Lunar-G. (4) COTS cameras will record the motion of regolith and tracer particles. Post-flight analysis of the videos will be used to determine convey speeds and flow rates. The VLRC experiment will use the well-known technique of Particle Image Velocimetry (PIV) image analysis to determine the velocity of tracer particles entrained in the regolith flow. This velocity will be used to calculate the mass flow rate of the regolith being conveyed.

ISRU↗
NASA NTRS1973

Environmental control of lunar samples in the Lunar Receiving Laboratory

The contamination controls used in the Lunar Receiving Laboratory during the processing of lunar samples are described. Initially, the lunar sample containers were opened and the material was examined in a vacuum complex with approximated lunar surface conditions. The process of examining and distributing the samples from this vacuum complex was time consuming. During both Apollo 11 and 12 missions portions of the lunar samples were processed for allocation in a small sterile glove box in a dry nitrogena atmosphere. After Apollo 12 a new system was installed based upon the experience gained from the small glove box. The system uses dry nitrogen as an environmental blanket and has the capability of being sterilized and of maintaining this sterility.

Reynolds, M. A.↗
NASA NTRS1974

Dielectric comparison of lunar and terrestrial fines at lunar conditions

The dielectric properties of lunar fines 74241,2 in the audio-frequency range under lunarlike conditions are presented. Results suggest that volatiles are released during storage and transport of the lunar sample. Apparently, subsequent adsorption of volatiles on the sample surface alters its dielectric response. The assumed volatile influence disappears after evacuation. A comparison of the dielectric properties of lunar and terrestrial materials as a function of density, temperature, and frequency indicates that if the terrestrial sample analyzed were completely devoid of atmospheric moisture, it would present dielectric losses smaller than those of the lunar sample. It is concluded that density prevails over temperature as the controlling factor of dielectric permittivity in the lunar regolith and that dielectric losses vary slowly with depth.

Alvarez, R.↗
NASA NTRS1976

Investigation of the daytime lunar atmosphere for lunar synthesis program

Synthesis studies of the daytime lunar atmoshere were directed toward improved understanding of fundamental lunar atmospheric dynamics and the relationship of the detectable atmosphere to physical processes of the lunar surface and interior. The primary source of data is the Apollo 17 lunar surface mass spectrometer. The Ar40 is radiogenic and its escape rate from the lunar atmosphere requires release of a significant fraction (about 8%) of the argon produced from the decay of K40 within the moon. Furthermore the process of argon release from the solid moon is time varying and related to seismic activity. Most of the helium on the moon is due to release of implanted solar wind alpha particles from the regolith.

Hodges, R. R., Jr.↗
NASA NTRS1976

Apollo Experiment Report: Lunar-Sample Processing in the Lunar Receiving Laboratory High-Vacuum Complex

A high-vacuum complex composed of an atmospheric decontamination system, sample-processing chambers, storage chambers, and a transfer system was built to process and examine lunar material while maintaining quarantine status. Problems identified, equipment modifications, and procedure changes made for Apollo 11 and 12 sample processing are presented. The sample processing experiences indicate that only a few operating personnel are required to process the sample efficiently, safely, and rapidly in the high-vacuum complex. The high-vacuum complex was designed to handle the many contingencies, both quarantine and scientific, associated with handling an unknown entity such as the lunar sample. Lunar sample handling necessitated a complex system that could not respond rapidly to changing scientific requirements as the characteristics of the lunar sample were better defined. Although the complex successfully handled the processing of Apollo 11 and 12 lunar samples, the scientific requirement for vacuum samples was deleted after the Apollo 12 mission just as the vacuum system was reaching its full potential.

White, D. R.↗
NASA NTRS1979

Lunar multispectral maps - Part II of the lunar nearside

Images of the lunar surface are being obtained at several wavelengths using a silicon vidicon imaging system and ground-based telescopes. These images are recorded and processed in digital form so that quantitative information is preserved; their photometric precision has been shown to be 1% or better. Ratio images, calculated by dividing those obtained at two wavelengths (0.40/0.56 and 0.95/0.56 micron), were presented in an earlier article, and more are presented here for a total coverage of about 60% of the lunar frontside. Spatial resolution is about 2 km at the subearth point. A complex of distinct units is evident in the images. Earlier work with the reflectance spectrum of lunar materials indicates that for the most part these units are compositionally distinct. These digital images are being used by lunar geologists to interpret the history of the lunar surface.

Mccord, T. B.↗
NASA NTRS1981

A small scale lunar launcher for early lunar material utilization

A system for the launching of lunar derived oxygen or raw materials into low lunar orbit or to L2 for transfer to low earth orbit is presented. The system described is a greatly simplified version of the conventional and sophisticated approach suggested by O'Neill using mass drivers with recirculating buckets. An electromagnetic accelerator is located on the lunar surface which launches 125 kg 'smart' containers of liquid oxygen or raw materials into a transfer orbit. Upon reaching apolune a kick motor is fired to circularize the orbit at 100 km altitude or L2. These containers are collected and their payloads transferred to a tanker OTV. The empty containers then have their kick motors refurbished and then are returned to the launcher site on the lunar surface for reuse. Initial launch capability is designed for about 500T of liquid oxygen delivered to low earth orbit per year with upgrading to higher levels, delivery of lunar soil for shielding, or raw materials for processing given the demand.

Snow, W. R.↗
NASA NTRS1990

Design of a device to remove lunar dust from space suits for the proposed lunar base

The National Aeronautics and Space Administration plans to begin construction of a lunar base soon after the turn of the century. During the Apollo missions, lunar dust proved to be a problem because the dust adhered to all exposed material surfaces. Since lunar dust will be a problem during the establishment and operation of this base, the need exists for a device to remove the dust from space suits before the astronauts enter clean environments. The physical properties of lunar dust were characterized and energy methods for removing the dust were identified. Eight alternate designs were developed to remove the dust. The final design uses a brush and gas jet to remove the dust. The brush bristles are made from Kevlar fibers and the gas jet uses pressurized carbon dioxide from a portable tank. A throttling valve allows variable gas flow. Also, the tank is insulated with Kapton and electrically heated to prevent condensation of the carbon dioxide when the tank is exposed to the cold (- 240 F) lunar night.

Harrington, David↗
NASA NTRS1991

Experimental reduction of simulated lunar glass by carbon and hydrogen and implications for lunar base oxygen production

The most abundant element in lunar rocks and soils is oxygen which makes up approximately 45 percent by weight of the typical lunar samples returned during the Apollo missions. This oxygen is not present as a gas but is tightly bound to other elements in mineral or glass. When people return to the Moon to explore and live, the extraction of this oxygen at a lunar outpost may be a major goal during the early years of operation. Among the most studied processes for oxygen extraction is the reduction of ilmenite by hydrogen gas to form metallic iron, titanium oxide, and oxygen. A related process is proposed which overcomes some of the disadvantages of ilmenite reduction. It is proposed that oxygen can be extracted by direct reduction of native lunar pyroclactic glass using either carbon, carbon monoxide, or hydrogen. In order to evaluate the feasibility of this proposed process a series of experiments on synthetic lunar glass are presented. The results and a discussion of the experiments are presented.

Mckay, David S.↗
NASA NTRS1989

Lunar resources - Toward living off the lunar land

An overview is presented of possibilities for the exploitation of lunar materials already proven to exist by Apollo experience. It is noted that lunar soils contain various materials required for life support, construction, and transportation, but that the high cost of lifting material from the earth's surface suggests that, in the near term, lunar material should be considered for use both on the moon and in LEO. Lunar water production, farming, propellant production, and the production of glass, iron, aluminum, and silicon to be used in lunar construction are discussed. The role of solar power and the possibility of electrolysis of molten silicate as a means of producing oxygen and metals for use on the moon and in near-earth space are examined. The benefits of immediate investment in developmental technology (given extensive project lead times) are stressed.

Haskin, Larry A.↗
NASA NTRS1992

Imperfect fractional crystallization of the lunar magma ocean and formation of the lunar mantle: A realistic chemical approach

It is generally considered that lunar mare basalts were generated by the melting of a cumulate mantle formed in an early Moon-wide magma ocean or magmasphere. However, the nature and chemistry of this cumulate mantle and the logistics of its origin have remained elusive. Extensive studies of terrestrial layered mafic intrusions over the past sixty years have emphasized the imperfection of fractional crystallization and attendant crystal-crystal and crystal-liquid separation in a convecting magma chamber. These separations were similarly inefficient during evolution of the lunar magmasphere, allowing for the trapping of interstitial melt and entrainment of a small proportion of less-dense plagioclase into the more-dense mafic cumulate mush. Indeed, petrography of lunar highlands samples demonstrates this well for anorthosites (with 1-10 percent olivine). Therefore, we propose a 'realistic' model for the evolution of the lunar mantle, which takes these observations into consideration, by the imperfect fractional crystallization of an early lunar magma ocean.

Snyder, Gregory A.↗
NASA NTRS1992

First Lunar Outpost: Lunar habitat concepts and issues

Information is given in viewgraph form on concepts and issues relative to the lunar habitat of the First Lunar Outpost (FLO). The initial design is for a mission capability for a group of four on a lunar stay of 45 days (lunar day-night-day). Existing hardware is used where practical. The specific goals include reuse every six months, provision of solar flare protection, manned extravehicular activities, operation anywhere on the lunar surface, access to all hardware to provide for infinite life, and a design that allows for growth.

Elrod, Molly↗
NASA NTRS1992

High-resolution Earth-based lunar radar studies: Applications to lunar resource assessment

The lunar regolith will most likely be a primary raw material for lunar base construction and resource extraction. High-resolution radar observations of the Moon provide maps of radar backscatter that have intensity variations generally controlled by the local slope, material, and structural properties of the regolith. The properties that can be measured by the radar system include the dielectric constant, density, loss tangent, and wavelength scale roughness. The radar systems currently in operation at several astronomical observatories provide the ability to image the lunar surface at spatial resolutions approaching 30 m at 3.8 cm and 12.6 cm wavelengths and approximately 500 m at 70 cm wavelength. The radar signal penetrates the lunar regolith to a depth of 10-20 wavelengths so the measured backscatter contains contributions from the vacuum-regolith interface and from wavelength-scale heterogeneities in the electrical properties of the subsurface material. The three wavelengths, which are sensitive to different scale structures and scattering volumes, provide complementary information on the regolith properties. Aims of the previous and future observations include (1) analysis of the scattering properties associated with fresh impact craters, impact crater rays, and mantled deposits; (2) analysis of high-incidence-angle observations of the lunar mare to investigate measurement of the regolith dielectric constant and hence porosity; (3) investigation of interferometric techniques using two time-delayed observations of the same site, observations that require a difference in viewing geometry less than 0.05 deg and, hence, fortuitous alignment of the Earth-Moon system when visible from Arecibo Observatory.

Stacy, N. J. S.↗
NASA NTRS1992

Experimental, physical and numerical modeling of lunar regolith and lunar regolith structures

An extensive series of laboratory strength and deformation experiments have been performed on a lunar regolith simulant. Results of these experiments are compared to results from experiments on real lunar regolith from the Apollo and Luna missions to illustrate the suitability of this material in capturing the engineering properties lunar regolith. In addition, these results are used to calibrate a constitutive model used to describe its stress-strain behavior. This model, in conjunction with numerical analysis techniques, is used to predict the response i.e. material parameters) of lunar simulant under 1/6-g and low confining stress conditions. These tools are also used to predict the displacement response of a lunar soil embankment structure used to cover a first generation human habitat module, which might be used to accommodate the first astronauts revisiting the moon. These predictions are compared to physical models of this structure, which are tested in a geotechnical centrifuge in order to satisfy scaling relationships between prototype and model.

Perkins, Steven W.↗
NASA NTRS1989

Mechanical properties of lunar regolith and lunar soil simulant

Through the Surveyor 3 and 7, and Apollo 11-17 missions a knowledge of the mechanical properties of Lunar regolith were gained. These properties, including material cohesion, friction, in-situ density, grain-size distribution and shape, and porosity, were determined by indirect means of trenching, penetration, and vane shear testing. Several of these properties were shown to be significantly different from those of terrestrial soils, such as an interlocking cohesion and tensile strength formed in the absence of moisture and particle cementation. To characterize the strength and deformation properties of Lunar regolith experiments have been conducted on a lunar soil simulant at various initial densities, fabric arrangements, and composition. These experiments included conventional triaxial compression and extension, direct tension, and combined tension-shear. Experiments have been conducted at low levels of effective confining stress. External conditions such as membrane induced confining stresses, end platten friction and material self weight have been shown to have a dramatic effect on the strength properties at low levels of confining stress. The solution has been to treat these external conditions and the specimen as a full-fledged boundary value problem rather than the idealized elemental cube of mechanics. Centrifuge modeling allows for the study of Lunar soil-structure interaction problems. In recent years centrifuge modeling has become an important tool for modeling processes that are dominated by gravity and for verifying analysis procedures and studying deformation and failure modes. Centrifuge modeling is well established for terrestrial enginering and applies equally as well to Lunar engineering. A brief review of the experiments is presented in graphic and outline form.

Steven W Perkins↗
NASA NTRS1993

The first lunar outpost: The design reference mission and a new era in lunar science

The content of the First Lunar Outpost (FLO) Design Reference Mission has been formulated and a 'strawman' science program has been established. The mission consists of two independent launches using heavy lift vehicles that land directly on the lunar surface. A habitat module and support systems are flown to the Moon first. After confirmation of a successful deployment of the habitat systems, the crewed lunar lander is launched and piloted to within easy walking distance (2 km) of the habitat. By eliminating the Apollo style lunar orbit rendezvous, landing sites at very high latitudes can be considered. A surface rover and the science experiments will accompany the crew. The planned stay time is 45 days, two lunar days and one night. A payload of 3.3 metric tons will support a series of geophysics, geology, astronomy, space physics, resource utilization, and life science experiments. Sample return is 150 to 200 kg. The rover is unpressurized and can carry four astronauts or two astronauts and 500 kg of payload. The rover can also operate in robotic mode with the addition of a robotics package. The science and engineering experiment strategy is built around a representative set of place holder experiments.

Lofgren, Gary E.↗
NASA NTRS1994

Preliminary solutions for the lunar gravity field from analysis of lunar orbiter tracking data

Knowledge of the gravitation field, in combination with surface topography, provides one of the principal means of inferring the internal structure of a planetary body. Previous analyses of the lunar gravitational field have been based on data from the Lunar Orbiters, the Apollo subsatellites, and the low altitude passes of the Apollo spacecraft. Recently, Konopliv et al. have reanalyzed all available Lunar Orbiter and Apollo subsatellite tracking data, producing a 60th degree and order solution. In preparation for the Clementine Mission to the Moon, we have also initiated a reanalysis of the Lunar Orbiter and Apollo subsatellite data. Our reanalysis takes advantage of advanced force and measurement modeling techniques as well as modern computational facilities. We applied the least squares collocation technique which stabilizes the behavior of the solution and high degree and order. The extension of the size of the field reduces the aliasing coming from the omitted portion of the gravitational field. This is especially important for the analysis of the tracking data from the Lunar Orbiters, as the periapse heights frequently ranged from 50 to 100 km.

Lemoine, F. G.↗
NASA NTRS2004

Lunar and Planetary Science XXXV: Lunar Geophysics: Rockin' and a-Reelin'

This document contained the following topics: The Influence of Tidal, Despinning, and Magma Ocean Cooling Stresses on the Magnitude and Orientation of the Moon#s Early Global Stress Field; New Approach to Development of Moon Rotation Theory; Lunar Core and Tides; Lunar Interior Studies Using Lunar Prospector Line-of-Sight Acceleration Data; A First Crustal Thickness Map of the Moon with Apollo Seismic Data; New Events Discovered in the Apollo Lunar Seismic Data; More Far-Side Deep Moonquake Nests Discovered; and Manifestation of Gas-Dust Streams from Double Stars on Lunar Seismicity.

Source record↗