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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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At least 577 records · Page 32
All sourcesNASA NTRSDOE OSTI
NASA NTRS2013

Testing and Analytical Modeling for Purging Process of a Cryogenic Line

To gain confidence in developing analytical models of the purging process for the cryogenic main propulsion systems of upper stage, two test series were conducted. The test article, a 3.35 m long with the diameter of 20 cm incline line, was filled with liquid or gaseous hydrogen and then purged with gaseous helium (GHe). Total of 10 tests were conducted. The influences of GHe flow rates and initial temperatures were evaluated. The Generalized Fluid System Simulation Program (GFSSP), an in-house general-purpose fluid system analyzer computer program, was utilized to model and simulate selective tests. The test procedures, modeling descriptions, and the results are presented in the following sections.

Hedayat, A.↗
NASA NTRS2014

Mass and Volume Optimization of Space Flight Medical Kits

Resource allocation is a critical aspect of space mission planning. All resources, including medical resources, are subject to a number of mission constraints such a maximum mass and volume. However, unlike many resources, there is often limited understanding in how to optimize medical resources for a mission. The Integrated Medical Model (IMM) is a probabilistic model that estimates medical event occurrences and mission outcomes for different mission profiles. IMM simulates outcomes and describes the impact of medical events in terms of lost crew time, medical resource usage, and the potential for medically required evacuation. Previously published work describes an approach that uses the IMM to generate optimized medical kits that maximize benefit to the crew subject to mass and volume constraints. We improve upon the results obtained previously and extend our approach to minimize mass and volume while meeting some benefit threshold. METHODS We frame the medical kit optimization problem as a modified knapsack problem and implement an algorithm utilizing dynamic programming. Using this algorithm, optimized medical kits were generated for 3 mission scenarios with the goal of minimizing the medical kit mass and volume for a specified likelihood of evacuation or Crew Health Index (CHI) threshold. The algorithm was expanded to generate medical kits that maximize likelihood of evacuation or CHI subject to mass and volume constraints. RESULTS AND CONCLUSIONS In maximizing benefit to crew health subject to certain constraints, our algorithm generates medical kits that more closely resemble the unlimited-resource scenario than previous approaches which leverage medical risk information generated by the IMM. Our work here demonstrates that this algorithm provides an efficient and effective means to objectively allocate medical resources for spaceflight missions and provides an effective means of addressing tradeoffs in medical resource allocations and crew mission success parameters.

Monte Carlo Method↗
NASA NTRS2014

Hot Hydrogen Testing of Tungsten-Uranium Dioxide (W-UO2) CERMET Fuel Materials for Nuclear Thermal Propulsion

CERMET fuel materials are being developed at the NASA Marshall Space Flight Center for a Nuclear Cryogenic Propulsion Stage. Recent work has resulted in the development and demonstration of a Compact Fuel Element Environmental Test (CFEET) System that is capable of subjecting depleted uranium fuel material samples to hot hydrogen. A critical obstacle to the development of an NCPS engine is the high-cost and safety concerns associated with developmental testing in nuclear environments. The purpose of this testing capability is to enable low-cost screening of candidate materials, fabrication processes, and further validation of concepts. The CERMET samples consist of depleted uranium dioxide (UO2) fuel particles in a tungsten metal matrix, which has been demonstrated on previous programs to provide improved performance and retention of fission products1. Numerous past programs have utilized hot hydrogen furnace testing to develop and evaluate fuel materials. The testing provides a reasonable simulation of temperature and thermal stress effects in a flowing hydrogen environment. Though no information is gained about radiation damage, the furnace testing is extremely valuable for development and verification of fuel element materials and processes. The current work includes testing of subscale W-UO2 slugs to evaluate fuel loss and stability. The materials are then fabricated into samples with seven cooling channels to test a more representative section of a fuel element. Several iterations of testing are being performed to evaluate fuel mass loss impacts from density, microstructure, fuel particle size and shape, chemistry, claddings, particle coatings, and stabilizers. The fuel materials and forms being evaluated on this effort have all been demonstrated to control fuel migration and loss. The objective is to verify performance improvements of the various materials and process options prior to expensive full scale fabrication and testing. Post test analysis will include weight percent fuel loss, microscopy, dimensional tolerance, and fuel stability.

Hickman, Robert↗
NASA NTRS2015

Testing and Analytical Modeling for Purging Process of a Cryogenic Line

To gain confidence in developing analytical models of the purging process for the cryogenic main propulsion systems of upper stage, two test series were conducted. The test article, a 3.35 m long with the diameter of 20 cm incline line, was filled with liquid or gaseous hydrogen and then purged with gaseous helium (GHe). Total of 10 tests were conducted. The influences of GHe flow rates and initial temperatures were evaluated. The Generalized Fluid System Simulation Program (GFSSP), an in-house general-purpose fluid system analyzer computer program, was utilized to model and simulate selective tests. The test procedures, modeling descriptions, and the results are presented in the following sections.

Hedayat, A.↗
NASA NTRS2016

ASTAR Flight Test: Overview and Spacing Results

The purpose of the NASA Langley Airborne Spacing for Terminal Arrival Routes (ASTAR) research aboard the Boeing ecoDemonstrator aircraft was to demonstrate the use of NASA's ASTAR algorithm using contemporary tools of the Federal Aviation Administration's Next Generation Air Transportation System (NEXTGEN). EcoDemonstrator is a Boeing test program which utilizes advanced experimental equipment to accelerate the science of aerospace and environmentally friendly technologies. The ASTAR Flight Test provided a proof-of-concept flight demonstration that exercised an algorithmic-based application in an actual aircraft. The test aircraft conducted Interval Management operations to provide time-based spacing off a target aircraft in non-simulator wind conditions. Work was conducted as a joint effort between NASA and Boeing to integrate ASTAR in a Boeing supplied B787 test aircraft while using a T-38 aircraft as the target. This demonstration was also used to identify operational risks to future flight trials for the NASA Air Traffic Management Technology Demonstration expected in 2017.

Roper, Roy D.↗
NASA NTRS2016

Development Of VHF (240-270 MHz) Antennas For SoOp (Signal Of Opportunity) Receiver For 6u Cubesat Platforms

The main goal of this research is to design, fabricate, and test deployable VHF antennas for 6U Cubesat platforms to enable validation of root zone soil moisture (RZSM) estimation algorithms for signal of opportunity (SoOp) remote sensing over the 240-270 MHz frequency band. The proposed work provides a strong foundation for establishing a technology development path for maturing a truly global direct surface soil moisture (SM) and RZSM measurement system (Figure 1) over a variety of land covers with limited density restrictions. In SoOp methodology, signals transmitted by already existing transmitters (known as transmitters of opportunity, in this case the Military Satellite Communication (MilSatCom) System's UHF Follow-On program) are utilized to measure properties of reflecting targets by recording reflected signals using a simple passive microwave receiver.

Cubesat↗
NASA NTRS2017

Gradient Compression Garments as a Countermeasure to Post-Space Flight Orthostatic Intolerance: Potential Interactions with the Maximum Absorbency Garment

Astronauts and cosmonauts may experience symptoms of orthostatic intolerance during re-entry, landing, and for several days post-landing following short- and long-duration spaceflight. Presyncopal symptoms have been documented in approximately 20% of short-duration and greater than 60% of long-duration flyers on landing day specifically during 5-10 min of controlled (no countermeasures employed at the time of testing) stand tests or 80 deg head-up tilt tests. Current operational countermeasures to orthostatic intolerance include fluid loading prior to and whole body cooling during re-entry as well as compression garments that are worn during and for up to several days after landing. While both NASA and the Russian space program have utilized compression garments to protect astronauts and cosmonauts traveling on their respective vehicles, a "next-generation" gradient compression garment (GCG) has been developed and tested in collaboration with a commercial partner to support future space flight missions. Unlike previous compression garments used operationally by NASA that provide a single level of compression across only the calves, thighs, and lower abdomen, the GCG provides continuous coverage from the feet to below the pectoral muscles in a gradient fashion (from approximately 55 mm Hg at the feet to approximately 16 mmHg across the abdomen). The efficacy of the GCG has been demonstrated previously after a 14-d bed rest study without other countermeasures and after short-duration Space Shuttle missions. Currently the GCG is being tested during a stand test following long-duration missions (~6 months) to the International Space Station. While results to date have been promising, interactions of the GCG with other space suit components have not been examined. Specifically, it is unknown whether wearing the GCG over NASA's Maximum Absorbency Garment (MAG; absorbent briefs worn for the collection of urine and feces while suited during re-entry and landing) will interfere with the effectiveness of the GCG or conversely whether the GCG will reduce the fluid absorption capabilities of the MAG. Methods: This operational, directed study, will (1) determine whether the effectiveness of the GCG is affected by the MAG with regard to cardiovascular responses to head-up tilt, the standard orthostatic intolerance test employed for astronauts and bed rest subjects; (2) determine whether the effectiveness of the MAG is compromised by the GCG tested by injecting a standard fluid volume (950 ml in 3 separate simulated "urine voids") at a standardized rate (30 ml/sec); and (3) determine whether comfort is affected by wearing the MAG under the GCG using a standardized questionnaire. Results from this study will guide future development and operational use of the GCG and MAG to maximize crew health, safety, and comfort.

Lee, S. M. C.↗
NASA NTRS2016

Hot-Fire Test Results of Liquid Oxygen/RP-2 Multi-Element Oxidizer-Rich Preburners

As part of the Combustion Stability Tool Development project funded by the Air Force Space and Missile Systems Center, the NASA Marshall Space Flight Center was contracted to assemble and hot-fire test a multi-element integrated test article demonstrating combustion characteristics of an oxygen/hydrocarbon propellant oxidizer-rich staged-combustion engine thrust chamber. Such a test article simulates flow through the main injectors of oxygen/kerosene oxidizer-rich staged combustion engines such as the Russian RD-180 or NK-33 engines, or future U.S.-built engine systems such as the Aerojet-Rocketdyne AR-1 engine or the Hydrocarbon Boost program demonstration engine. To supply the oxidizer-rich combustion products to the main injector of the integrated test article, existing subscale preburner injectors from a previous NASA-funded oxidizer-rich staged combustion engine development program were utilized. For the integrated test article, existing and newly designed and fabricated inter-connecting hot gas duct hardware were used to supply the oxidizer-rich combustion products to the oxidizer circuit of the main injector of the thrust chamber. However, before one of the preburners was used in the integrated test article, it was first hot-fire tested at length to prove it could provide the hot exhaust gas mean temperature, thermal uniformity and combustion stability necessary to perform in the integrated test article experiment. This paper presents results from hot-fire testing of several preburner injectors in a representative combustion chamber with a sonic throat. Hydraulic, combustion performance, exhaust gas thermal uniformity, and combustion stability data are presented. Results from combustion stability modeling of these test results are described in a companion paper at this JANNAF conference, while hot-fire test results of the preburner injector in the integrated test article are described in another companion paper.

Protz, C. S.↗
NASA NTRS2016

LAVA Pressure Transducer Trade Study

The Regolith and Environment Science and Oxygen and Lunar Volatile Extraction (RESOLVE) payload will transport the (LAVA) subsystem to hydrogen-rich locations on the moon supporting NASA's in-situ resource utilization (ISRU) programs. There, the LAVA subsystem will analyze volatiles that evolve from heated regolith samples in order to quantify how much water is present. To do this, the system needs resilient pressure transducers (PTs) to calculate the moles in the gas samples. The PT trade study includes a comparison of newly-procured models to a baseline unit with prior flight history in order to determine the PT model with the best survivability in flight-forward conditions.

Trade Study↗
NASA NTRS2018

NASA 2018 Green Propulsion Roadmap

The Green Propulsion Working Group (GPWG) is a technical guidance working group formed April 2017 under the Agency's Capability Leadership Team The GPWG was tasked with recommending an agency road map and providing guidance to NASA on green propulsion technology development and infusion The GPWG's efforts focus on ionic liquid propellants and related technologies The GPWG was chartered with three representatives from NASA Centers currently exploring green propulsion technologies As other Centers may explore programs that utilize green propulsion, membership of the working group can be expanded to include more interested parties Working group also solicits and coordinates with other government agencies (e.g. AFRL, MDA) In 2015, JANNAF hosted a Technical Interchange Meeting (TIM) on Green Monopropellant Alternatives to Hydrazine (GMAH) Included both Government and non-Government contributions on the State-of-the-Art in Green Propulsion Technology Following the TIM, a Government-only session (USAF/AFRL/NASA/MDA/DLA) reviewed and identified remaining technical gaps in Green Propulsion In 2016, an inter-agency team (AFRL/NASA/MDA) worked together to develop an informal inter-agency "roadmap" based on the outcome of the TIM Approach consisted of near-term, mid-term, and long-term technology advancement areas, approaching incrementally larger thrust classes The NASA Green Propulsion Working Group reviewed the work of the 2016 Inter-Agency Working Group, and concurs that the identified technical gaps and technology development areas are still relevant and necessary to see green propulsion technology advanced The GPWG recommends the 2016 roadmap be adopted as baseline for NASA needs, with some additions The focus of the 2016 inter-agency roadmap was primarily on the thruster technology. The Agency must also invest in understanding the broader propulsion system-level technology gaps in parallel. Timeframes are considered suggested from a priority standpoint, but are also flexible as some efforts will need to occur in the nearer term or concurrently in order to meet specific mission requirements The GPWG developed 2018 roadmap breaks down the technology development goals into Technology Development Areas (TDA's), and identifies the near-, mid, and long-term sub-goals within those areas. Those TDA's are: Thruster Hardware Development Modeling & Tools Development Materials Properties and Compatibility Propellant Development.

Cavender, Dan↗
NASA NTRS2019

Experimental Facility to Measure Power and Forces to Excavate Lunar Regolith Simulants

An Excavation Lab has been built at the NASA Glenn Research Center in support of the NASA In-Situ Resource Utilization (ISRU) program objectives to measure the power and forces needed to excavate granular lunar regolith. The data obtained will be used to validate excavation models used in system studies and for developing light weight, energy efficient digging devices for activities on the moon and mars. The Excavation Lab houses the Advanced Planetary Excavator (APEX), an electrically actuated backhoe arm with a bucket, which is used to dig GRC-3B, a simulant of granular lunar regolith comprised of silica sand and silt. A load cell is mounted between the arm and the bucket to measure digging forces. Dig trajectories files are created and used to control the APEX for repeatability. Comparison of preliminary data recorded for the same trajectory in air and in GRC-3B shows measurable difference in power and load cell measurements. Load cell forces for a linear dig in GRC-3B are presented.

Excavation↗
NASA NTRS2019

TPSAS-NF1676L-32540-DND

The supersonic/hypersonic ground testing serves a multitude of purposes and objectives. From structural and material integrity, to force and moment models; from pressure mapping, thermal imaging, shock structure to scramjet/ramjet engine operability and ignition studies. Hypersonics has become more of a high profile area of late. Compared to flight testing, ground testing typically it is less expensive and usually is not a one single-test test program. It is more forgiving in the fact that a test program can utilize a single test article and get data from a number of tests. Ground test data is the input to the formation of research databases, as well as, validation of CFD models/tools. To understand the output, one must first understand the inputs. To achieve supersonic/hypersonic speeds the use of compressors or compressed air storage along with converging-diverging nozzles are needed. Flight temperatures also need to be achieved for the ground test to truly simulate flight conditions. At NASA Langley's 8' High Temperature Tunnel (HTT), compressed natural gas (methane) is burned to heat the air. To validate that the desired test condition is met, test instrumentation is used and data is collected from the combustor all the way through the nozzle exit plane. In this talk, NASA Langley's 8' HTT will be the basis for what kind of test capabilities hypersonic ground testing offers. It certainly does not offer every capability within ground testing, nor will the discussion cover all types. Specific test techniques used and data collection methods will be discussed and how these confirm certain flight conditions have been achieved. There will be subsequent thoughts on experimental methods that aid test articles such as thrust stands, model actuation, etc.

Aaron W Fuchs↗
NASA NTRS1994

VAPEPS Management Center

VAPEPS is a computer program that utilizes statistical energy analysis (SEA) theory and SEA extrapolation methods to predict the vibroacoustic environments in complex systems.

vibroacoustic↗
NASA NTRSDate not supplied

Sustainable Power for the Lunar Surface

The Propulsion and Power Systems Alliance promotes programmatic and technical collaboration between government agencies in order to better utilize existing program resources in the areas of power and propulsion. This presentation will provide other government agencies an idea of the ongoing work at NASA GRC for power, focusing on the use of a microgrid for sustainable lunar surface power and autonomous power control development for the lunar surface microgrid.

Jeffrey Csank↗
NASA NTRSDate not supplied

An Integrated Recursive Framework for Arbitrarily Multiscale and Multi-fidelity Modeling

The NASA Multiscale Analysis Tool (NAMSAT) serves as a state-of-the-art, “plug and play,” massively multiscale modeling (M3) platform for hierarchical materials and structures. The development of NASMAT has focused on modularity, upgradability and maintainability, interoperability, and utility. Application Program Interfaces (APIs) have been developed to facilitate the integration NASMAT into other programs (commercial, research, and user-defined) as well as the integration of other codes into NASMAT. NASMAT is an integrated, recursive platform that seamlessly allows for an arbitrary number of scales, and a variety of modeling fidelity, in a single, non-linear analysis. Thus, the macroscopic response of a material can be directly linked to the behavior of the microstructure(s), including subscale defects, making it a suitable tool for integrated computational materials engineering (ICME) because . Examples using NASMAT for simulation of polycrystalline metals at elevated temperatures will be presented.

Multiscale Modeling↗
NASA NTRSDate not supplied

Design Study of a Nuclear-Electric Transport Vehicle for Ice Giant Missions

Nuclear-electric propulsion, in which a nuclear reactor is used to power high specific-impulse ion thrusters for propulsion, is a promising method for such applications as missions to the ice giants Uranus and Neptune, identified as targets of high science value in the most recent NASA Decadal Survey of Planetary Science. Until recently, however, this has required a lightweight space nuclear power system that has yet to be designed. NASA has recently been developing the “Kilopower” nuclear reactor as a power source for future exploration missions, with a 1-kW prototype recently tested under the KRUSTY program. We utilized a next-generation Kilopower reactor to design a transportation system for missions to the ice giant planets. The mission objectives were to carry a payload of 1164 kg, comprising a lander/hopper vehicle to be delivered to explore the moon or moons of the target ice giant, along with atmospheric probes to drop into the atmosphere, plus 188 kg of science instrumentation on the spacecraft itself.

nuclear electric propulsion↗
NASA NTRSDate not supplied

Summary of NASA Progress on the Development and Qualification of a 12-kW Hall-Effect, Solar Electric Propulsion Thruster

Beginning in 2014, the National Aeronautics and Space Administration (NASA) Space Technology Mission Directorate (STMD) began a project to increase the state of the art for the Hall-Effect Solar Electric Propulsion (SEP) technology. The Technology Demonstration Missions (TDM) Program Office provides programmatic oversight of SEP with the project being led by Glenn Research Center, supported by the Jet Propulsion Laboratory and development, qualification & flight hardware all provided by Aerojet Rocketdyne (AR). This technology was pursued as the propulsion system for the Asteroid Redirect and Robotic Mission (ARRM). While the concept was originally slated for ARRM, it was realigned to Gateway to support future Moon to Mars objectives. The Gateway lunar station was established and will play a key role in NASA’s Artemis Program which utilizes collaboration with the Canadian Space Agency (CSA), the European Space Agency (ESA) and the Japanese Space Agency (JAXA). The 12-kW hardware will be the primary propulsion for the Gateway element, Power & Propulsion Element (PPE), from Low Earth Orbit to a Near Rectilinear Halo Orbit around the Moon. Initial efforts began with utilizing Technology Development Units (TDU) built by NASA as the predecessor to the contract activity with AR. Over the past few years, AR has built Engineering Test Units (ETU), Engineering Development Units (EDU) and qualification & flight models (QM and FM, respectively). With requirement changes from the AARM mission to PPE, the joint team has modified the design and has started qualification activities for environment testing (shock, vibe) at multiple facilities in the US leading to eventual life testing. This paper will explore the various design changes, system modeling and the latest status for qualification testing.

Joel Robinson↗
NASA NTRSDate not supplied

Summary of NASA Progress on the Development and Qualification of a 12 kW Hall Effect, Solar Electric Propulsion Thruster

Beginning in 2014, the National Aeronautics and Space Administration (NASA) Space Technology Mission Directorate (STMD) began a project to increase the state of the art for the Hall-Effect Solar Electric Propulsion (SEP) technology. The Technology Demonstration Missions (TDM) Program Office provides programmatic oversight of SEP with the project being led by Glenn Research Center, supported by the Jet Propulsion Laboratory and development, qualification & flight hardware all provided by Aerojet Rocketdyne (AR). This technology was pursued as the propulsion system for the Asteroid Redirect and Robotic Mission (ARRM). While the concept was originally slated for ARRM, it was realigned to Gateway to support future Moon to Mars objectives. The Gateway lunar station was established and will play a key role in NASA’s Artemis Program which utilizes collaboration with the Canadian Space Agency (CSA), the European Space Agency (ESA) and the Japanese Space Agency (JAXA). The 12-kW hardware will be the primary propulsion for the Gateway element, Power & Propulsion Element (PPE), from Low Earth Orbit to a Near Rectilinear Halo Orbit around the Moon. Initial efforts began with utilizing Technology Development Units (TDU) built by NASA as the predecessor to the contract activity with AR. Over the past few years, AR has built Engineering Test Units (ETU), Engineering Development Units (EDU) and qualification & flight models (QM and FM, respectively). With requirement changes from the AARM mission to PPE, the joint team has modified the design and has started qualification activities for environment testing (shock, vibe) at multiple facilities in the US leading to eventual life testing. This paper will explore the various design changes, system modeling and the latest status for qualification testing.

Joel W Robinson↗