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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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NASA NTRS1997

In Situ Resource Utilization (ISRU II) Technical Interchange Meeting

This volume contains extended abstracts that have been accepted for presentation at the In Situ Resource Utilization (ISRU II) Technical Interchange Meeting, November 18-19, 1997, at the Lunar and Planetary Institute, Houston, Texas. Included are topics which include: Extraterrestrial resources, in situ propellant production, sampling of planetary surfaces, oxygen production, water vapor extraction from the Martian atmosphere, gas generation, cryogenic refrigeration, and propellant transport and storage.

David Kaplan↗
NASA NTRS2017

Robust Exploration and Commercial Missions to the Moon Using LANTR Propulsion and Lunar Liquid Oxygen Derived from FeO-Rich Pyroclastic Deposits

Studies conducted by NASA and its contractors (early 1980s early 1990s) indicated a substantial benefit from using lunar-derived propellants specifically lunar-derived LO2 (LLO2) or LUNOX in a lunar space transportation system (LTS). With a LTS using LO2/LH2 chemical rockets, approx. 6 kilograms (kg) of mass in low Earth orbit (LEO) is required to place 1 kg of payload on the lunar surface (LS). Of this 6 kg, approx. 70% (4.2 kg) is propellant and 6/7th of this mass (3.6 kg) is oxygen assuming an O/H MR 6:1. Since the cost of placing a kilogram of mass on the LS is approx. 6X the cost of delivering it to LEO, the ability to produce and utilize LUNOX or lunar-derived LO2 and hydrogen (LLH2) from lunar polar ice (LPI) deposits can provide significant mission leverage. Providing LUNOX for use in fuel cells, life support systems and LO2/LH2 chemical rockets used on lunar landing vehicles (LLVs), can allow high value cargo (people, manufacturing and scientific equipment, etc.) to be transported to LEO, then to the Moon instead of bulk LO2 propellant. Oxygen is abundant in the lunar regolith (approx. 43% by mass) and can be extracted using a variety of techniques, such as hydrogen reduction of ilmenite (FeOTiO2) or FeO-rich volcanic glass (orange soil) discovered during the Apollo 17 mission to Taurus-Littrow. While considerable interest has been expressed about mining and processing LPI for rocket propellant, ground truth must first be established to quantify the physical state of the ice (e.g., its vertical thickness and areal extent, levels of soil contamination, etc.) and the deep, extremely cold (approx. 26-100 K) permanently shadowed craters where the ice resides.

Nuclear Thermal Propulsion↗
NASA NTRSDate not supplied

NASA Plans for In Situ Resource Utilization (ISRU) Development, Demonstration, and Implementation

The United States (US) National Aeronautics and Space Administration’s (NASA) Artemis Moon to Mars program has four major goals: (1) Returning Americans to the Moon: 1st Woman & 1st Person of Color, (2) Learning to live and work on the Moon, (3) Translating lessons learned so that the United States has capabilities and operational experience for a mission to Mars, and (4) Inspires the next generation of explorers, researchers, scientists, and engineers worldwide. Overarching all of this, the NASA Artemis program also continues to follow Space Policy Directive One (SPD-1) which directs the US to lead an innovative and sustainable exploration program with commercial and international partners. A major objective to achieve the Artemis program goals and SPD-1 is to understand and characterize the resources that exist at these destinations, and to learn how to utilize these resources for sustained human exploration and the commercialization of space. This ability, commonly known as In Situ Resource Utilization (ISRU), involves any hardware or operation that harnesses and utilizes local resources to create products and services for robotic and human explo-ration. The NASA ISRU program is focused on the production of mission consumables and com-modities to enable sustained human exploration, such as rocket propellants, life support consuma-bles, fuel cell reactants, feedstock for manufacturing and construction, and nutrients for food and plant growth. In particular, propellants make up a significant fraction of the mass launched from Earth, are critical to mission success, and can reduce the cost for reusable transportation. Important for enabling long term surface stays, greater independence from Earth, and growing lunar infra-structure are the abilities to perform construction and manufacturing from in situ-derived metals and materials to create and expand on the infrastructure and reduce the logistical resupply needed for sustained surface and space operations. To achieve these ISRU capabilities, NASA, in partner-ship with industry, academia, and international partners has initiated a multi-faceted program which involves (i) Determining Customer Needs (Type and Quantity of Commodities), (ii) supporting ground Development of Hardware and Systems until Ready for Lunar Flight, (iii) utilize Commer-cial Lunar Payload Services (CLPS) flights to fly resource assessment missions with the Science Mission Directorate (SMD), and public-private partnership (PPP) ISRU demonstrations of critical technologies and processes, and (iv) performing commercial-led end-to-end ‘Pilot’ Plant production of commodities and demonstration of usage at a scale and duration that minimizes or eliminates risk for full implementation of ISRU-derived commodities in mission critical applications. This paper will discuss the technologies, mission studies, and accomplishments achieved to date for the ISRU multi-faceted program, and plans for continued ground development and flight missions to reduce the risk of full ISRU implementation.

In situ resource utilization↗
NASA NTRS2012

Modular Flooring System

The modular flooring system (MFS) was developed to provide a portable, modular, durable carpeting solution for NASA fs Robotics Alliance Project fs (RAP) outreach efforts. It was also designed to improve and replace a modular flooring system that was too heavy for safe use and transportation. The MFS was developed for use as the flooring for various robotics competitions that RAP utilizes to meet its mission goals. One of these competitions, the FIRST Robotics Competition (FRC), currently uses two massive rolls of broadloom carpet for the foundation of the arena in which the robots are contained during the competition. The area of the arena is approximately 30 by 72 ft (approximately 9 by 22 m). This carpet is very cumbersome and requires large-capacity vehicles, and handling equipment and personnel to transport and deploy. The broadloom carpet sustains severe abuse from the robots during a regular three-day competition, and as a result, the carpet is not used again for competition. Similarly, broadloom carpets used for trade shows at convention centers around the world are typically discarded after only one use. This innovation provides a green solution to this wasteful practice. Each of the flooring modules in the previous system weighed 44 lb (.20 kg). The improvements in the overall design of the system reduce the weight of each module by approximately 22 lb (.10 kg) (50 %), and utilize an improved "module-to-module" connection method that is superior to the previous system. The MFS comprises 4-by-4-ft (.1.2-by- 1.2-m) carpet module assemblies that utilize commercially available carpet tiles that are bonded to a lightweight substrate. The substrate surface opposite from the carpeted surface has a module-to-module connecting interface that allows for the modules to be connected, one to the other, as the modules are constructed. This connection is hidden underneath the modules, creating a smooth, co-planar flooring surface. The modules are stacked and strapped onto durable, commercially available drywall carts for storage and/or transportation. This method of storage and transportation makes it very convenient and safe when handling large quantities of modules.

Thate, Robert↗
NASA NTRS1971

Field evaporation ion source with possible application to electrostatic propulsion

Field evaporation of solid metal electrodes has been proposed as an ion source for an electrostatic propulsion device. The chief advantage over existing ion sources is the prospect of 100 percent fuel utilization efficiency. This advantage arises as a result of the elimination of the need for a gaseous precursor state for propellant ionization. The attainment of required high surface field strengths is achieved through field-induced extrusion of the electrode geometry at elevated temperatures. Contributions of both surface and bulk transport mechanisms are taken into account.

Weizer, V. G.↗
NASA NTRS1979

Solar energy collection system

A fixed, linear, ground-based primary reflector having an extended curved sawtooth-contoured surface covered with a metalized polymeric reflecting material, reflects solar energy to a movably supported collector that is kept at the concentrated line focus reflector primary. The primary reflector may be constructed by a process utilizing well known freeway paving machinery. The solar energy absorber is preferably a fluid transporting pipe. Efficient utilization leading to high temperatures from the reflected solar energy is obtained by cylindrical shaped secondary reflectors that direct off-angle energy to the absorber pipe. A seriatim arrangement of cylindrical secondary reflector stages and spot-forming reflector stages produces a high temperature solar energy collection system of greater efficiency.

Miller, C. G.↗
NASA NTRS1990

Design and fabrication of instrumented composite airfoils for a cryogenic wind tunnel model

Two instrumented horizontal stabilizers and one instrumented vertical stabilizer were designed and fabricated for testing on the Pathfinder 1 (PF-1) Transport Model in the NASA Langley Research Center's National Transonic Facility (NTF). Two different designs were employed: the horizontal stabilizer utilized a metal spar and fiberglass overwrap and the vertical stabilizer was made of all fiberglass. All design requirements were met in terms of design loads, airfoil tolerances, surface finish, orifice hole quality, and proof-of-concept tests. Pressure tubing installation was found to be easier for these concepts as compared to methods used in conventional metallic models. Ease of repair was found to be a principal advantage in that some fabrication problems were overcome by reapplying fiberglass cloth and/or epoxy to damaged areas. Also, fabrication costs were judged to be lower when compared to the more conventional design fabrication costs.

Young, Clarence P., Jr.↗
NASA NTRS2004

Microscale Investigation of Thermo-Fluid Transport in the Transition FIL, Region of an Evaporating Capillary Meniscus Using a Microgravity Environment

In order to enhance the fundamental understanding of thin film evaporation and thereby improve the critical design concept for two-phase heat transfer devices, microscale heat and mass transport is to be investigated for the transition film region using state-of-the-art optical diagnostic techniques. By utilizing a microgravity environment, the length scales of the transition film region can be extended sufficiently, from submicron to micron, to probe and measure the microscale transport fields which are affected by intermolecular forces. Extension of the thin film dimensions under microgravity will be achieved by using a conical evaporator made of a thin silicon substrate under which concentric and individually controlled micro-heaters are vapor-deposited to maintain either a constant surface temperature or a controlled temperature variation. Local heat transfer rates, required to maintain the desired wall temperature boundary condition, will be measured and recorded by the concentric thermoresistance heaters controlled by a Wheatstone bridge circuit, The proposed experiment employs a novel technique to maintain a constant liquid volume and liquid pressure in the capillary region of the evaporating meniscus so as to maintain quasi-stationary conditions during measurements on the transition film region. Alternating use of Fizeau interferometry via white and monochromatic light sources will measure the thin film slope and thickness variation, respectively. Molecular Fluorescence Tracking Velocimetry (MFTV), utilizing caged fluorophores of approximately 10-nm in size as seeding particles, will be used to measure the velocity profiles in the thin film region. An optical sectioning technique using confocal microscopy will allow submicron depthwise resolution for the velocity measurements within the film for thicknesses on the order of a few microns. Digital analysis of the fluorescence image-displacement PDFs, as described in the main proposal, can further enhance the depthwise resolution.

Kihm, K. D.↗
NASA NTRS2018

Space Resources and Mining: Current Objectives, Plans, and Missions

Why are Space Resources and Their Use Important? There are many reasons why people and nations want to explore space, and there are many different ways in which space can be explored. A critical interface linking both the ‘why’ and the ‘how’ of space exploration is the identification, extraction, and use of resources in space. In both NASA’s Journey to Mars: Pioneering Next Steps in Space Exploration released in October of 2015 and the Global Exploration Roadmap released in August 2013, the ability to find, quantify, extract, process, and use space resources was identified as a critical objective by NASA and over 14 other space agencies for achieving affordable and sustainable human exploration beyond Earth’s orbit, encouraging and creating new commercial entities and markets based on space activities, and increasing the terrestrial economy and quality-of-life benefits for all humankind. Robotic and especially human space exploration up to this point in time can be considered to be ‘Earth reliant’ in that everything needed to support and enable the mission is launched from Earth. The past Apollo missions to the Moon and the International Space Station currently in orbit above the Earth all rely on hardware, habitats, power, transportation, and life support consumables sent from Earth to keep the crew alive and working. As the distance from Earth increases, the cost of transportation and the risks due to failures and logistics disruptions also increases. By using resources found at the site of exploration to make mission critical consumables (such as propellants, fuel cell reactants and life support commodities), spare parts, and infrastructure needed to support surface activities (such as landing pads, roads, habitats/shelters, and power/thermal systems) commonly referred to as In Situ Resource Utilization, a significant amount of launch mass and cost can be saved and risk reduced. The ability to do these things also changes how exploration is performed from Earth Reliant to NASA’s goal of ‘Earth Independent’ exploration. After the US Apollo program was over, people began to recognize that it had been an inspiration for a generation of young students to go into Science, Technology, Engineering and Math (STEM) fields, and that the US industry and economy had significantly grown and lived off these students and the technological advances made to achieve these missions for decades. Space exploration should no longer be focused solely on scientific advancement or national pride, but for economic growth and population standard of living advancement. Considering the economic value of human exploration and how it could expand the economy of the US was brought to full light in a speech by John Marburger, the director of US Office of Science and Technology Policy under George W Bush at the Goddard Symposium in 2006. In his speech he highlighted that the ultimate goal was not to just Explore space but to Use space for the benefit of mankind. He further stated that the use of off-planet resources, in this case from the Moon, should be a critical architectural consideration for human space exploration to make it more affordable and sustainable. This could be achieved in two ways. The first is to start by encouraging and commercializing the extraction and production of transportation and life support related products from space resources, which could than lead to other resource uses once an affordable transportation architecture is established. The second is to encourage the spin-in of terrestrial technologies into space applications and spin-off of space technologies into terrestrial applications to increase the efficiency and profitability of terrestrial industries.

Sanders, Gerald B.↗
NASA NTRS2018

The Utilization Profiles of the CCSDS Unified Space Link Protocol (USLP)

The purpose of this paper is to identify the utilization profiles for interfacing the Data Protocol Sublayer using the Unified Space Link Protocols (USLP) (reference 1) with the space link coding procedures as specified in the CCSDS Coding & Synchronization Blue Books (references 2 through 5), used in both telecommand and telemetry applications. This paper describes how the USLP Protocol utilizes the coding and synchronization sublayer to support: a. Direct to Earth (DTE) telemetry links for engineering and science data b. Direct to Earth (DTE) telemetry links for very high rate science data c. Direct from Earth (DFE) command, sequencing and flight software loads d. Space to Space Links (Proximity) utilized by orbiters for data exchange to/from surface bound assets. The CCSDS has divided the functions of the Data Link Layer into two sublayers: the Data Link Protocol Sublayer (DLP-SL) and the Coding and Synchronization Sublayer (CS-SL). The Data Link Protocol Sublayer (DLP-SL) interfaces to the users, accepting the data that is to be transported, on the sending side of the link, and delivering that data on the receiving end. The Transfer Frame is the data unit that is transferred across the Data Link Protocol Sublayer and the Coding and Synchronization Sublayer boundary. The Coding and Synchronization Sublayer (CS-SL) provides the encoding, randomization, and frame synchronization functions that prepares the USLP Transfer Frame for transport across the space link. The CS-SL is divided into 2 processes: 1) The Frame Interface Processes (FIP) performs the interface functions required to prepare the data for delivery to the Coding/Decoding Process (CDP). This process includes prepending a Frame Start Marker to the provided frame, when management has designated that the frame is not to be aligned to the codeblock or when there is no block code used. 2) The Coding/Decoding Process (CDP) performs the forward error correction processes that are used to optimize the performance of the link and minimize the error rate. The CDP creates the symbol stream that is delivered to the Physical Layer. The transfer of the USLP transfer frames across different types of space links is the focus of this paper. The Protocol Data Unit (PDU) that is passed in both directions between the Data Link Protocol Sublayer (DLP-SL) and Coding and Synchronization Sublayer (CS-SL) is the transfer frame. The USLP frame structure provides flexibility that can be constrained by the functions utilized within the CS-SL that prepare the transfer frame for transit. For example, the USLP transfer frame contains a length field that enables the frame to be of variable length but CS-SL under certain conditions may constrain the frame to be fixed in length. This paper describes 5 operational modes available for use by the Data Link Layer to provide data exchange across the USLP space link. These modes are different because different operational requirements apply to vastly different types of space links and thus the communications implementation requirements differ. The environmental issues include the power or energy available, the distance between the end points of the link, the complexity of the equipment available at those end points, the atmospheric conditions and radiometric frequency selection. The CS-SL utilizes different forward error correcting codes supported by specific operational modes to configure the data for transit. This paper describes all of the operational modes in a series of data models which decompose the functionality between the Data Link Protocol Sublayer and the Coding and Synchronization sublayer. The operational modes described are: 1. Uncoded Mode: has been used for short links that contain significant available power to provide an acceptable frame error rate. The frames in this mode can be variable in length and typically use an error detection algorithm (i.e., CRC) to determine if there are errors in the received frame. 2. Convolutional Only Mode: is currently the prime forward error correction coding used for the proximity links. The frames in this mode can be variable in length and typically use an error detection algorithm (i.e., CRC) to determine if there are errors in the received frame. 3. Variable Length Frame Aligned to Variable Length Codeblock (TC): is used for Direct from Earth links were power levels are high and the simple, least complex code i.e., the BCH code is used. This mode has been in use since the early 1970s. The BCH code is a short code and the decoder is easy to implement. 4. Fixed Length Frame Aligned to Fixed Length Codeblock (AOS/TM): was introduced when the concatenated Convolutional and Reed-Solomon Code was formulated to provide significant reduction in link data error rate and the ability to determine if there was an error in the decoded codeblock. The frame is aligned to the codeblock so that there is a one to one relationship of frame errors to codeblock errors without additional error detection coding being added. This mode requires the protocol frames to be the exact size of the message portion of the codeblock. 5. Frames Unaligned to Fixed Length Codeblocks (Currently used for very high rates and space to space links): This mode is currently used for missions that have a very high data rate that can be controlled adaptively as the environment changes and as the next generation operating mode for the proximity link. This mode from a coded data stream point of view is exactly like that described in 4. above, except that the frame need not be aligned to the codeblock. There is no requirement on frame length when using this mode. Thus when using USLP it can be used to support links that require short or long frames. There is also no mandatory requirement that frames cannot be separated by idle data reducing the tight data rate connection requirements between the data link protocol sublayer and the coding & synchronization sublayer. In conclusion, how these operational modes can be put to use in mission operational scenarios is described for Direct from Earth links (DFE), Direct to Earth links (DTE), and Proximity links.

Greenberg, E.↗
NASA NTRS1990

Simulator comparison of thumball, thumb switch, and touch screen input concepts for interaction with a large screen cockpit display format

A piloted simulation study was conducted comparing three different input methods for interfacing to a large screen, multiwindow, whole flight deck display for management of transport aircraft systems. The thumball concept utilized a miniature trackball embedded in a conventional side arm controller. The multifunction control throttle and stick (MCTAS) concept employed a thumb switch located in the throttle handle. The touch screen concept provided data entry through a capacitive touch screen installed on the display surface. The objective and subjective results obtained indicate that, with present implementations, the thumball concept was the most appropriate for interfacing with aircraft systems/subsystems presented on a large screen display. Not unexpectedly, the completion time differences between the three concepts varied with the task being performed, although the thumball implementation consistently outperformed the other two concepts. However, pilot suggestions for improved implementations of the MCTAS and touch screen concepts could reduce some of these differences.

Jones, Denise R.↗
NASA NTRS2020

Impacts of Water Clarity Variability on Temperature and Biogeochemistry in the Chesapeake Bay

Estuarine water clarity depends on the concentrations of aquatic constituents, such as colored dissolved organic matter, phytoplankton, inorganic suspended solids, and detritus, which are influenced by variations in riverine inputs. These constituents directly affect temperature because when water is opaque, sunlight heats a shallower layer of the water compared to when it is clear. Despite the importance of accurately predicting temperature variability, many numerical modeling studies do not adequately account for this key process. In this study, we quantify the effect of water clarity on heating by comparing two simulations of a hydrodynamic-biogeochemical model of the Chesapeake Bay for the years 2001–2005, in which (1) water clarity is constant in space and time for the computation of solar heating, compared to (2) a simulation where water clarity varies with modeled concentrations of light-attenuating materials. In the variable water clarity simulation, the water is more opaque, particularly in the northern region of the Bay. This decrease in water clarity reduces the total heat, phytoplankton, and nitrate throughout the Bay. During the spring and summer months, surface temperatures in the northern Bay are warmer by 0.1 °C and bottom temperatures are colder by 0.2 °C in the variable light attenuation simulation. Warmer surface temperatures encourage phytoplankton growth and nutrient uptake near the head of the Bay, and fewer nutrients are transported downstream. These impacts are greater during higher river flow years, when differences in temperature, nutrients, phytoplankton, and zooplankton extend further seaward compared to other years. This study demonstrates the consequences of utilizing different light calculations for estuarine heating and biogeochemistry.

water clarity↗
NASA NTRS2018

Don't Forget About... (Factoring in Everything for Successful Mars Exploration): In Situ Resource Utilization

Using In Situ Resources means reduced transportation requirements from Earth and a larger source of materials than might otherwise be available. Of the many in situ resources available on Mars, perhaps the most valuable is water. One facet of NASA's current Mars Exploration Program is a search for the locations and quantities of water in various forms: Subsurface liquid water aquafers; Surface and subsurface water ice and icy soils - Lineated Valley Fill (LVF), Lobate Debris Aprons (LDAs), Concentric Crater Fill (CCF); Hydrated minerals - Chlorides, Phyllosilicates, Sulfates, etc.; "Average regolith." Access to massive quantities of water could change surface mission concepts of operation and drive site selection. Availability of massive quantities of water could enable or change current assumptions for: Propellant manufacturing; Radiation protection;- "Relaxed" requirements for a closed loop ECLSS (Environmental Control and Life Support System); Crop growth; Improved crew amenities, such as more frequent showers and laundry.

ISRU↗
NASA NTRS1992

Utilizing a Space Station as a transportation node in a lunar exploration program

A strategy for using a Space Station as a lunar transportation node is described. One possibility is to use the Space Station for both launch and recovery of the lunar spacecraft and crew. The approach examined here is to launch the lunar spacecraft and crew from the Space Station; but, on return, the crew would go directly to the earth surface in a capsule, while the lunar spacecraft would slowly rendezvous with the Space Station. This approach retains the major advantages of the Space Station as a transportation node but eliminates or greatly reduces its major disadvantages.

Wagner, Lynn A., Jr.↗
NASA NTRS2018

Potential Advantages of Conducting Short Duration Visits to the Martian Surface

Recent NASA concepts for human missions to Mars, including the Evolvable Mars Campaign and Design Reference Architecture 5.0, have focused on the conduct of missions with long duration stays on the Martian surface. The decision to focus on long duration missions (typically to a single site) is driven by a desire to increase the perceived sustainability of the human Mars campaign, predicated on the assumption that sustainability is best achieved by maximizing the level of activity on the surface, providing for continuous growth in operations, and promoting pioneering of Mars. However, executing a series of long duration missions to a single site is not the only option for human exploration of Mars that has been proposed. Other architectures have been evaluated that focus on missions with short duration surface stays, with each mission visiting a separate site on the surface. This type of architecture is less efficient in that elements are not typically reused from one mission to the next but requires a far less complex surface architecture. There are potentially valid arguments to be made that a short duration, multiple site approach could result in different types of advantages when compared to the long duration, single site approach to Mars exploration, particularly for initial human missions to Mars. These arguments revolve around four areas: Achieved Value, Risk Mitigation, Developmental Affordability, and Operational Affordability & Flexibility. The question of Achieved Value relates to the prioritization of goals for Martian exploration. As discussed, goals related to pioneering and expanding human presence are often referenced as justifications for the long duration approach. However, there are other competing goals, including science and exploration. While there is not a clear consensus among planetary scientists, many have argued that the value of being able to visit multiple sites could outweigh the value of continually visiting a single site. Risk Mitigation is a major concern for initial human missions to Mars. There are a number of hazards related to operating on the Martian surface that are not well characterized. It may be desirable to conduct a series of short duration missions to better understand the nature of these risks prior to committing to a long duration mission. Developmental Affordability relates to the ability of NASA and its partners to develop and deploy the proposed architecture. Any human missions to Mars will be among the most complex endeavors ever undertaken. The capabilities that must be developed to enable any human Mars missions are extremely challenging. The total design, development, test, and evaluation (DDT&E) budget required to develop just the essential capabilities alone will be substantial. If additional surface capabilities are required to support long duration surface stays, the development effort could be unaffordable. Operational Affordability & Flexibility relates to the continued costs to execute the Mars campaign. Long duration missions, even with some amount of in-situ resource utilization, require a significant level of resupply for every mission. This requires additional launches and in-space transportation assets, increasing the operational complexity and total operational cost. This paper will explore each of the four potential advantages of short duration missions in detail. The authors will present comparisons between proposed long duration and short duration architectures through an evaluation of relevant performance, cost, and risk metrics.

Stromgren, Chel↗
NASA NTRS2011

Space Transportation Infrastructure Supported By Propellant Depots

A space transportation infrastructure is described that utilizes propellant depots to support all foreseeable missions in the Earth-Moon vicinity and deep space out to Mars. The infrastructure utilizes current expendable launch vehicles such as the Delta IV Heavy, Atlas V, and Falcon 9, for all crew, cargo, and propellant launches to orbit. Propellant launches are made to a Low-Earth-Orbit (LEO) Depot and an Earth-Moon Lagrange Point 1 (L1) Depot to support new reusable in-space transportation vehicles. The LEO Depot supports missions to Geosynchronous Earth Orbit (GEO) for satellite servicing, and to L1 for L1 Depot missions. The L1 Depot supports Lunar, Earth-Sun L2 (ESL2), Asteroid, and Mars missions. A Mars Orbital Depot is also described to support ongoing Mars missions. New concepts for vehicle designs are presented that can be launched on current 5-meter diameter expendable launch vehicles. These new reusable vehicle concepts include a LEO Depot, L1 Depot, and Mars Orbital Depot based on International Space Station (ISS) heritage hardware. The high-energy depots at L1 and Mars orbit are compatible with, but do not require, electric propulsion tug use for propellant and/or cargo delivery. New reusable in-space crew transportation vehicles include a Crew Transfer Vehicle (CTV) for crew transportation between the LEO Depot and the L1 Depot, a new reusable Lunar Lander for crew transportation between the L1 Depot and the lunar surface, and a Deep Space Habitat (DSH) to support crew missions from the L1 Depot to ESL2, Asteroid, and Mars destinations. A 6 meter diameter Mars lander concept is presented that can be launched without a fairing based on the Delta IV heavy Payload Planners Guide, which indicates feasibility of a 6.5 meter fairing. This lander would evolve to re-usable operations when propellant production is established on Mars. Figure 1 provides a summary of the possible missions this infrastructure can support. Summary mission profiles are presented for each primary mission capability. These profiles are the basis for propellant loads, numbers of vehicles/stages and launches for each mission capability. Data includes the number of launches required for each mission utilizing current expendable launch vehicle systems, and concluding remarks include ideas for reducing the number of launches through incorporation of heavy-lift launch vehicles, solar electric propulsion, and other transportation support concepts.

Smitherman, David↗
NASA NTRS2024

Evaluation of 10‐m Wind Speed From ISD Meteorological Stations and the MERRA‐2 Reanalysis: Impacts on Dust Emission in the Arabian Peninsula

Mineral dust is one of the most important aerosols when studying the radiative balance and climate of the planet. There are different dust emission schemes utilized by the atmospheric modeling communities, many of which disagree on basic output quantities such as mass of dust emitted and distribution of mass among size bins. In this work, we examined mineral dust emission from a leading model scheme, the Goddard Chemistry Aerosol Radiation and Transport (GOCART), as utilized in the Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) Reanalysis and compared it to dust emissions calculated using wind measurements from ground based weather stations located in the Arabian Peninsula that are included in the National Oceanic and Atmospheric Administration’s (NOAA) integrated surface database (ISD). An intercomparison of 10-m wind speed is shown for the Arabian Peninsula region, differences of the observed and modeled wind field are quantified, and impacts of differences on dust emissions are calculated. This analysis shows 10-m winds in the ISD were generally lower than MERRA-2 winds, which propagated to dust emissions errors. Our estimate of one of the most significant mass impacts in dust emission is 0.178 Tg/year/grid box with a percent change of over 200% to the recalculated dust emissions from MERRA-2. These differences in wind speed propagated to a difference in dust mass emitted by the use of a static source function which aids in scaling the mass emitted by the availability of dust in each grid. Additionally, the magnitude of these differences varies seasonally.

winds↗
NASA NTRS2005

DEVELOPMENT OF STANDARDIZED LUNAR REGOLITH SIMULANT MATERIALS

Lunar exploration activities require scientific and engineering studies that use standardized testing procedures and ultimately support flight certification of hardware and the development of technologies for their use on the lunar surface. It is necessary to anticipate the full range of source materials and environmental constraints that are expected on the Moon and Mars, and to evaluate in-situ resource utilization (ISRU) coupled with testing and development. Historical use of lunar simulants has focused on physical aspects of the lunar regolith for landing and transportation activities. Lunar mare simulants MLS-1 and JSC-1 have been developed, but supplies have been exhausted. Renewed emphasis on exploration and ISRU activities requires development of standardized simulant reference materials that are traceable interlaboratory standards for testing and simulate the lunar regolith in terms of physical, chemical, and mineralogical properties. This new generation of lunar regolith simulants must therefore support both technological development and testing methods. These issues were extensively discussed at the 2005 Lunar Regolith Simulant Materials Workshop.

Carpenter, P.↗