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At least 253 records · Page 14
All sourcesNASA NTRSDOE OSTI
NASA NTRS2003

The Evolution of Oblique Impact Flow Fields Using Maxwell's Z Model

Oblique impacts are the norm rather than the exception for impact craters on planetary surfaces. This work focuses on the excavation of experimental oblique impact craters using the NASA Ames Vertical Gun Range (AVGR). Three-dimensional particle image velocimetry (3D PIV) is used to obtain quantitative data on ejection positions, three dimensional velocities and angles. These data are then used to constrain Maxwell's Z Model and follow the subsurface evolution of the excavation-stage flow-field center during oblique impacts.

Anderson, J. L. B.↗
NASA NTRS2003

New Insights into the Geology of the Mars Pathfinder Landing Site from Spectral and Morphologic Analysis of the 12-Color Superpan Panorama

New analyses of rocks and soils at the Mars Pathfinder landing site have been completed using the full Imager for Mars Pathfinder (IMP) 12- color SuperPan panorama. These revise early conclusions that rocks at the landing site are a single lithology coated only by windblown dust. We conclude instead that there is also a second lithology in addition to the dominant gray rock, and that it is consistent with highlands material excavated from beneath a thin veneer of northern plains; that many rocks have cemented coatings that formed during an early, probably wetter climate; and that young rocks excavated after coating formation ceased are mainly breccias or conglomerates.

S Murchie↗
NASA NTRS2003

The Evolution of Oblique Impact Flow Fields Using Maxwell's Z Model

Oblique impacts are the norm rather than the exception for impact craters on planetary surfaces. This work focuses on the excavation of experimental oblique impact craters using the NASA Ames Vertical Gun Range (AVGR). Three-dimensional particle image velocimetry (3D PIV) is used to obtain quantitative data on ejection positions, three-dimensional velocities and angles. These data are then used to test the applicability and limitations of Maxwell's Z Model in representing the subsurface evolution of the excavation-stage flow-field center during vertical and oblique impacts.

Anderson, J. L. B.↗
NASA NTRS2004

Ground Ice at the Phoenix Landing Site: A Preflight Assessment

One of the objectives of the Mars Scout mission, Phoenix, is to characterize the present state of water in the martian environment, in a location where water may play a significant role in the present and past habitability of Mars. Given the generally dry and cold climate of Mars today any substantial amount of water is expected to occur in the form of ground ice (subsurface ice) within the regolith. The Mars Odyssey Gamma Ray Spectrometer has indicated abundant subsurface hydrogen and inferred ground ice at high latitudes. Therefore, the Phoenix mission will be targeted to land in the northern high latitudes (approximately 65 degrees N - 75 degrees N) where ground ice is expected to be abundantly available for analysis. The lander will be capable of excavating, sampling, and analyzing, dry and water-rich/icy soils. The location and depth of excavation necessary to achieve the goals of sampling and analysis of icy material become important parameters to assess. In the present work we ask two key questions: 1) At what depth within the regolith do we expect to find ice? 2) How might this depth vary over the region of potential landing sites? Numerous lines of evidence can be employed to provide an indication of the presence or absence of shallow ground ice at the potential landing sites. For example geomorphology, neutrons, gamma rays, and theory each contribute clues to an overall understanding of the distribution of ice. Orbital observations provide information on a variety of spatial scales, typically 10 s of meters (patterned ground) to 100 s of kilometers (gamma rays). While information on all of these scales are important, of particular interest is how the presence and depth of ground ice might vary on spatial scales comparable to the lander and its work area. While ground ice may be stable (and present) on a regional scale, local-scale slopes and changes in the physical characteristics of soils can result in significant variations in the distribution of ice.

Mellon, M. T.↗
NASA NTRS2005

The Lunar-wide Effects of the Formation of Basins on the Megaregolith

The surface of the Moon underwent an intense bombardment during the first approx.700 my of it s history (e.g. [1]). During this time at least 43 basins [1,2] and countless smaller craters were formed across the entire surface [1,3]. A quantitative assessment of the regolith as formed and modified by basins is discussed here. The formation of the basins (craters >300km in diameter) caused a significant amount of material to be excavated and redistributed across the surface of the Moon [4,5,6,7]. The material excavated by each individual basin was deposited and laterally mixed with the surrounding surface. This resulted in the development of a lunar-wide mixed zone of fragmented material, several kilometers thick [5,8,9]. This mixed zone was developed further by subsequent impacts resulting in a fragmental zone 1-2km thick called the megaregolith [10]. The initial zone of mixed material formed by the basins is not expected to be uniform across the surface of the Moon because of the varied size and random distribution of the basins. The main topographic ring of the 43 basins discussed by Wilhelms and Spudis [1,2] are illustrated in Figure 1.

Petro, . E.↗
NASA NTRS2008

A Versatile Lifting Device for Lunar Surface Payload Handling, Inspection and Regolith Transport Operations

Devices for lifting and transporting payloads and material are critical for efficient Earth-based construction operations. Devices with similar functionality will be needed to support lunar-outpost construction, servicing, inspection, regolith excavation, grading and payload placement. Past studies have proposed that only a few carefully selected devices are required for a lunar outpost. One particular set of operations involves lifting and manipulating payloads in the 100 kg to 3,000 kg range, which are too large or massive to be handled by unassisted astronauts. This paper will review historical devices used for payload handling in space and on earth to derive a set of desirable features for a device that can be used on planetary surfaces. Next, an innovative concept for a lifting device is introduced, which includes many of the desirable features. The versatility of the device is discussed, including its application to lander unloading, servicing, inspection, regolith excavation and site preparation. Approximate rules, which can be used to size the device for specific payload mass and reach requirements, are provided. Finally, details of a test-bed implementation of the innovative concept, which will be used to validate the structural design and develop operational procedures, is provided.

Doggett, William R.↗
NASA NTRS2010

Exploring Martian Impact Craters: Why They are Important for the Search for Life

Fluvial features and evidence for aqueous alteration indicate that Mars was wet, at least partially and/or periodically, in the Noachian. Also, impact cratering appears to have been the dominant geological process [1] during that epoch. Thus, investigation of Noachian craters will further our understanding of this geologic process, its effects on the water-bearing Martian crust, and any life that may have been present at the time. Impact events disturbed and heated the water- and/or ice-bearing crust, likely initiated long-lived hydrothermal systems [2-4], and formed crater lakes [5], creating environments suitable for life [6]. Thus, Noachian impact craters are particularly important exploration targets because they provide a window into warm, water-rich environments of the past which were possibly conducive to life. In addition to the presence of lake deposits, assessment of the presence of hydrothermal deposits in the walls, floors and uplifts of craters is important in the search for life on Mars. Impact craters are also important for astrobiological exploration in other ways. For example, smaller craters can be used as natural excavation pits, and so can provide information and samples that would otherwise be inaccessible (e.g., [7]). In addition, larger (> ~75 km) craters can excavate material from a potentially habitable region, even on present-day Mars, located beneath a >5-km deep cryosphere.

Schwenzer, S. P.↗
NASA NTRS2010

Quick Attach Docking Interface for Lunar Electric Rover

The NASA Lunar Electric Rover (LER) has been developed at Johnson Space Center as a next generation mobility platform. Based upon a twelve wheel omni-directional chassis with active suspension the LER introduces a number of novel capabilities for lunar exploration in both manned and unmanned scenarios. Besides being the primary vehicle for astronauts on the lunar surface, LER will perform tasks such as lunar regolith handling (to include dozing, grading, and excavation), equipment transport, and science operations. In an effort to support these additional tasks a team at the Kennedy Space Center has produced a universal attachment interface for LER known as the Quick Attach. The Quick Attach is a compact system that has been retro-fitted to the rear of the LER giving it the ability to dock and undock on the fly with various implements. The Quick Attach utilizes a two stage docking approach; the first is a mechanical mate which aligns and latches a passive set of hooks on an implement with an actuated cam surface on LER. The mechanical stage is tolerant to misalignment between the implement and the LER during docking and once the implement is captured a preload is applied to ensure a positive lock. The second stage is an umbilical connection which consists of a dust resistant enclosure housing a compliant mechanism that is optionally actuated to mate electrical and fluid connections for suitable implements. The Quick Attach system was designed with the largest foreseen input loads considered including excavation operations and large mass utility attachments. The Quick Attach system was demonstrated at the Desert Research And Technology Studies (D-RA TS) field test in Flagstaff, AZ along with the lightweight dozer blade LANCE. The LANCE blade is the first implement to utilize the Quick Attach interface and demonstrated the tolerance, speed, and strength of the system in a lunar analog environment.

Schuler, Jason M.↗
NASA NTRS2009

Lunar Regolith Simulant Feed System for a Hydrogen Reduction Reactor System

One of the goals of In-Situ Resource Utilization (ISRU) on the moon is to produce oxygen from the lunar regolith which is present in the form of Ilmenite (FeTi03) and other compounds. A reliable and attainable method of extracting some of the oxygen from the lunar regolith is to use the hydrogen reduction process in a hot reactor to create water vapor which is then condensed and electrolyzed to obtain oxygen for use as a consumable. One challenge for a production system is to reliably acquire the regolith with an excavator hauler mobility platform and then introduce it into the reactor inlet tube which is raised from the surface and above the reactor itself. After the reaction, the hot regolith (-1000 C) must be expelled from the reactor for disposal by the excavator hauler mobility system. In addition, the reactor regolith inlet and outlet tubes must be sealed by valves during the reaction in order to allow collection of the water vapor by the chemical processing sub-system. These valves must be able to handle abrasive regolith passing through them as well as the heat conduction from the hot reactor. In 2008, NASA has designed and field tested a hydrogen reduction system called ROxygen in order to demonstrate the feasibility of extracting oxygen from lunar regolith. The field test was performed with volcanic ash known as Tephra on Mauna Kea volcano on the Big Island of Hawai'i. The tephra has similar properties to lunar regolith, so that it is regarded as a good simulant for the hydrogen reduction process. This paper will discuss the design, fabrication, operation, test results and lessons learned with the ROxygen regolith feed system as tested on Mauna Kea in November 2008.

Mueller, R. P.↗
NASA NTRS2011

Experimental Testing and Modeling of a Pneumatic Regolith Delivery System for ISRU

Excavating and transporting planetary regolith are examples of surface activities that may occur during a future space exploration mission to a planetary body. Regolith, whether it is collected on the Moon, Mars or even an asteroid, consists of granular minerals, some of which have been identified to be viable resources that can be mined and processed chemically to extract useful by-products, such as oxygen, water, and various metals and metal alloys. Even the depleted "waste" material from such chemical processes may be utilized later in the construction of landing pads and protective structures at the site of a planetary base. One reason for excavating and conveying planetary regolith is to deliver raw regolith material to in-situ resource utilization (ISRU) systems. The goal of ISRU is to provide expendable supplies and materials at the planetary destination, if possible. An in-situ capability of producing mission-critical substances such as oxygen will help to extend the mission and its success, and will greatly lower the overall cost of a mission by either eliminating, or significantly reducing, the need to transport the same expendable materials from the Earth. In order to support the goals and objectives of present and future ISRU projects, NASA seeks technology advancements in the areas of regolith conveying. Such systems must be effective, efficient and provide reliable performance over long durations while being exposed to the harsh environments found on planetary surfaces. These conditions include contact with very abrasive regolith particulates, exposure to high vacuum or dry (partial) atmospheres, wide variations in temperature, reduced gravity, and exposure to space radiation. Regolith conveying techniques that combine reduced failure modes and low energy consumption with high material transfer rates will provide significant value for future space exploration missions to the surfaces of the moon, Mars and asteroids. Pneumatic regolith conveying has demonstrated itself to be a viable delivery system through testing under terrestrial and reduced gravity conditions in recent years. Modeling and experimental testing have been conducted at NASA Kennedy Space Center to study and advance pneumatic planetary regolith delivery systems in support of NASA's ISRU project. The goal of this work is to use the model to predict solid-gas flow patterns in reduced gravity environments for ISRU inlet gas line allowing the eductor inlet gas flow to vary and depend on the flow pattern developed at the eductor as inferred by the experimental observations.

Santiago-Maldonado, Edgardo↗
NASA NTRS2012

Site Tamper and Material Plow Tool - STAMP

A non-actuated tool has been developed for preparing regolith for in situ measurement by smoothing uneven surfaces and excavating fresher subsurface material for planetary exploration. The STAMP tool contains two tools to prepare regolith for in situ measurement: a tamper to smooth uneven surfaces, and a blade to excavate fresher subsurface material.

Aisen, Norman M.↗
NASA NTRS2012

Applying Biomimetic Algorithms for Extra-Terrestrial Habitat Generation

The objective is to simulate and optimize distributed cooperation among a network of robots tasked with cooperative excavation on an extra-terrestrial surface. Additionally to examine the concept of directed Emergence among a group of limited artificially intelligent agents. Emergence is the concept of achieving complex results from very simple rules or interactions. For example, in a termite mound each individual termite does not carry a blueprint of how to make their home in a global sense, but their interactions based strictly on local desires create a complex superstructure. Leveraging this Emergence concept applied to a simulation of cooperative agents (robots) will allow an examination of the success of non-directed group strategy achieving specific results. Specifically the simulation will be a testbed to evaluate population based robotic exploration and cooperative strategies while leveraging the evolutionary teamwork approach in the face of uncertainty about the environment and partial loss of sensors. Checking against a cost function and 'social' constraints will optimize cooperation when excavating a simulated tunnel. Agents will act locally with non-local results. The rules by which the simulated robots interact will be optimized to the simplest possible for the desired result, leveraging Emergence. Sensor malfunction and line of sight issues will be incorporated into the simulation. This approach falls under Swarm Robotics, a subset of robot control concerned with finding ways to control large groups of robots. Swarm Robotics often contains biologically inspired approaches, research comes from social insect observation but also data from among groups of herding, schooling, and flocking animals. Biomimetic algorithms applied to manned space exploration is the method under consideration for further study.

Birge, Brian↗
NASA NTRS2014

Geological Structures in the WaIls of Vestan Craters

A compelling case can be made that Vesta is the parent asteroid for the howardite, eucrite and diogenite (HED) meteorites [1], although this interpretation has been questioned [2]. Generalized models for the structure of the crust of Vesta have been developed based on petrologic studies of basaltic eucrites, cumulate eucrites and diogenites. These models use inferred cooling rates for different types of HEDs and compositional variations within the clan to posit that the lower crust is dominantly diogenitic in character, cumulate eucrites occur deep in the upper crust, and basaltic eucrites dominate the higher levels of the upper crust [3-5]. These models lack fine-scale resolution and thus do not allow for detailed predictions of crustal structure. Geophysical models predict dike and sill intrusions ought to be present, but their widths may be quite small [6]. The northern hemisphere of Vesta is heavily cratered, and the southern hemisphere is dominated by two 400-500 km diameter basins that excavated deep into the crust [7-8]. Physical modeling of regolith formation on 300 km diameter asteroids predicts that debris layers would reach a few km in thickness, while on asteroids of Vesta's diameter regolith thicknesses would be less [9]. This agrees well with the estimated ≤1 km thickness of local debris excavated by a 45 km diameter vestan crater [10]. Large craters and basins may have punched through the regolith/megaregolith and exposed primary vestan crustal structures. We will use Dawn Framing Camera (FC) [11] images and color ratio maps from the High Altitude and Low Altitude Mapping Orbits (HAMO, ~65 m/pixel; LAMO, ~20 m/pixel) to evaluate structures exposed on the walls of craters: two examples are discussed here.

Mittlefehldt, David↗
NASA NTRS2014

Asteroid 4 Vesta: A Fully Differentiated Dwarf Planet

One conclusion derived from the study of meteorites is that some of them - most irons, stony irons, some achondrites - hail from asteroids that were heated to the point where metallic cores and basaltic crusts were formed. Telescopic observations show that there remains only one large asteroid with a basaltic crust, 4 Vesta; present day mean radius 263 km. The largest clan of achondrites, the howardite, eucrite and diogenite (HED) meteorites, represent the crust of their parent asteroid. Diogenites are cumulate harzburgites and orthopyroxenites from the lower crust whilst eucrites are cumulate gabbros, diabases and basalts from the upper crust. Howardites are impact-engendered breccias of diogenites and eucrites. A strong case can be made that HEDs are derived from Vesta. The NASA Dawn spacecraft orbited Vesta for 14 months returning data allowing geological, mineralogical, compositional and geophysical interpretations of Vesta's surface and structure. Combined with geochemical and petrological observations of HED meteorites, differentiation models for Vesta can be developed. Proto-Vesta probably consisted of primitive chondritic materials. Compositional evidence, primarily from basaltic eucrites, indicates that Vesta was melted to high degree (>=50%) which facilitated homogenization of the silicate phase and separation of immiscible Fe,Ni metal plus Fe sulphide into a core. Geophysical models based on Dawn data support a core of ~110 km radius. The silicate melt vigorously convected and initially followed a path of equilibrium crystallization forming a harzburgitic mantle, possibly overlying a dunitic restite. Once the fraction of crystals was sufficient to cause convective lockup, the remaining melt collected between the mantle and the cool thermal boundary layer. This melt undergoes fractional crystallization to form a dominantly orthopyroxenite (diogenite) lower crust. The initial thermal boundary layer of primitive chondritic material is gradually replaced by a mafic crust through impact disruption and foundering. The quenched mafic crust thickens over time through magma extrusion/intrusion. Melt from the residual magma ocean intrudes and penetrates the mafic crust forming cumulate eucrite plutons, and dikes, sills and flows of basaltic eucrite composition. The post-differentiation vestan structure is thus not too dissimilar from that of terrestrial planets: (i) a metallic core; (ii) an ultramafic mantle comprised of a lower dunitic layer (if melting was substantially <100%) and an upper cumulate harzburgitic layer; (iii) a lower crust of harzburgitic and orthopyroxenitic cumulates; and (iv) an upper mafic crust of basalts and diabases (melt compositions) with cumulate gabbro intrusions. Impacts have excavated to the lower crust and delivered howardites, eucrites and diogenites to Earth, but there is yet no evidence demonstrating excavation of the vestan mantlle.

Mittlefehldt, David↗
NASA NTRS2014

Advanced Space Surface Systems Operations

The importance of advanced surface systems is becoming increasingly relevant in the modern age of space technology. Specifically, projects pursued by the Granular Mechanics and Regolith Operations (GMRO) Lab are unparalleled in the field of planetary resourcefulness. This internship opportunity involved projects that support properly utilizing natural resources from other celestial bodies. Beginning with the tele-robotic workstation, mechanical upgrades were necessary to consider for specific portions of the workstation consoles and successfully designed in concept. This would provide more means for innovation and creativity concerning advanced robotic operations. Project RASSOR is a regolith excavator robot whose primary objective is to mine, store, and dump regolith efficiently on other planetary surfaces. Mechanical adjustments were made to improve this robot's functionality, although there were some minor system changes left to perform before the opportunity ended. On the topic of excavator robots, the notes taken by the GMRO staff during the 2013 and 2014 Robotic Mining Competitions were effectively organized and analyzed for logistical purposes. Lessons learned from these annual competitions at Kennedy Space Center are greatly influential to the GMRO engineers and roboticists. Another project that GMRO staff support is Project Morpheus. Support for this project included successfully producing mathematical models of the eroded landing pad surface for the vertical testbed vehicle to predict a timeline for pad reparation. And finally, the last project this opportunity made contribution to was Project Neo, a project exterior to GMRO Lab projects, which focuses on rocket propulsion systems. Additions were successfully installed to the support structure of an original vertical testbed rocket engine, thus making progress towards futuristic test firings in which data will be analyzed by students affiliated with Rocket University. Each project will be explained in further detail, as well as the full scope of the contributions made during this opportunity.

Robotics↗
NASA NTRS2014

Characterizing the Physical and Thermal Properties of Planetary Regolith at Low Temperatures

The success or failure of in-situ resource utilization for planetary surface exploration-whether for science, colonization, or commercialization-relies heavily on the design and implementation of systems that can effectively process planetary regolith and exploit its potential benefits. In most cases, this challenge necessarily includes the characterization of regolith properties at low temperatures (cryogenic). None of the nearby solar system destinations of interest, such as the moon, Mars and asteroids, possess a sufficient atmosphere to sustain the consistently "high" surface temperatures found on Earth. Therefore, they can experience permanent cryogenic temperatures or dramatic cyclical changes in surface temperature. Characterization of physical properties (e.g., specific heat, thermal and electrical conductivity) over the entire temperature profile is important when planning a mission to a planetary surface; however, the impact on mechanical properties due to the introduction of icy deposits must also be explored in order to devise effective and robust excavation technologies. The Granular Mechanics and Regolith Operations Laboratory and the Cryogenics Test Laboratory at NASA Kennedy Space Center are developing technologies and experimental methods to address these challenges and to aid in the characterization of the physical and mechanical properties of regolith at cryogenic temperatures. This paper will review the current state of knowledge concerning planetary regolith at low temperature, including that of icy regolith, and describe efforts to manipulate icy regolith through novel penetration and excavation techniques.

Characterizing the Physical and Thermal Properties↗
NASA NTRS2011

The Role of Planetary Dust and Regolith Mechanics in Technology Developments at NASA

One of NASA's long term goals continues to be the exploration of other planets and orbital bodies in our solar system. Our sustained presence through the installation of stations or bases on these planetary surfaces will depend on developing properly designed habitation modules, mobility systems and supporting infrastructure. NASA Glenn Research Center is involved in several technology developments in support of this overarching goal. Two key developments are in the area of advanced filtration and excavation systems. The first addresses the issues posed by the accumulation of particulate matter over long duration missions and the intrusion of planetary dust into spacecraft and habitat pressurized cabins. The latter supports the operation and infrastructure of insitu resource utilization (ISRU) processes to derive consumables and construction materials from the planetary regolith. These two developments require a basic understanding of the lunar regolith at the micro (particle) to macro (bulk) level. Investigation of the relevant properties of the lunar regolith and characterization of the standard simulant materials used in. testing were important first steps in these developments. The fundamentals and operational concepts of these technologies as well as descriptions of new NASA facilities, including the Particulate Filtration Testing and the NASA Excavation and Traction Testing facilities, and their capabilities for testing and advancing these technologies will be presented. The test data also serves to validate and anchor computational simulation models.

Agui, Juan H.↗
NASA NTRS2015

RASSOR - Regolith Advanced Surface Systems Operations Robot

The Regolith Advanced Surface Systems Operations Robot (RASSOR) is a lightweight excavator for mining in reduced gravity. RASSOR addresses the need for a lightweight (<100 kg) robot that is able to overcome excavation reaction forces while operating in reduced gravity environments such as the moon or Mars. A nominal mission would send RASSOR to the moon to operate for five years delivering regolith feedstock to a separate chemical plant, which extracts oxygen from the regolith using H2 reduction methods. RASSOR would make 35 trips of 20 kg loads every 24 hours. With four RASSORs operating at one time, the mission would achieve 10 tonnes of oxygen per year (8 t for rocket propellant and 2 t for life support). Accessing craters in space environments may be extremely hard and harsh due to volatile resources - survival is challenging. New technologies and methods are required. RASSOR is a product of KSC Swamp Works which establishes rapid, innovative and cost effective exploration mission solutions by leveraging partnerships across NASA, industry and academia.

Regolith↗