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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 91 records · Page 5
All sourcesNASA NTRSDOE OSTI
NASA NTRS1977

Thermochemical water decomposition

At present, nearly all of the hydrogen consumed in the world is produced by reacting hydrocarbons with water. As the supply of hydrocarbons diminishes, the problem of producing hydrogen from water alone will become increasingly important. Furthermore, producing hydrogen from water is a means of energy conversion by which thermal energy from a primary source, such as solar or nuclear fusion of fission, can be changed into an easily transportable and ecologically acceptable fuel. The attraction of thermochemical processes is that they offer the potential for converting thermal energy to hydrogen more efficiently than by water electrolysis. A thermochemical hydrogen-production process is one which requires only water as material input and mainly thermal energy, or heat, as an energy input. Attention is given to a definition of process thermal efficiency, the thermodynamics of the overall process, the single-stage process, the two-stage process, multistage processes, the work of separation and a process evaluation.

Funk, J. E.↗
NASA NTRS2023

Mitigating Space Radiation Using Magnesium(-Lithium) and Boron Carbide Composites

The health effects of galactic cosmic radiation are a serious impediment to crewed exploration of the solar system. OLTARIS, an interface for the 3DHZETRN deterministic radiation transport code, was used to assess the response of aerospace materials to this constant radiation exposure. Traditional aerospace structural materials like aluminum can, after a certain mass, increase the health effects of such radiation. However, materials with lower atomic mass may mitigate this build-up in secondary radiation with increasing areal density. As such, lower atomic mass structural alloys of magnesium and magnesium–lithium are promising candidates. These alloys may reduce the mass of structures when substituted for aluminum alloys. Reinforcement with boron carbide could further reduce atomic mass while also improving the mechanical properties of such lightweight alloys. This study found that the lower atomic mass of these materials increased nuclear fragmentation upon cosmic radiation interactions, leading to a softening of the secondary (neutron) radiation spectra. This softened spectra reduced the effective dose equivalent, a measure of health effects, for magnesium(-lithium) alloys and their boron carbide-reinforced composites when compared to aluminum.

Galactic cosmic radiation↗
NASA NTRS2010

Overview of the Graphical User Interface for the GERMcode (GCR Event-Based Risk Model)

The descriptions of biophysical events from heavy ions are of interest in radiobiology, cancer therapy, and space exploration. The biophysical description of the passage of heavy ions in tissue and shielding materials is best described by a stochastic approach that includes both ion track structure and nuclear interactions. A new computer model called the GCR Event-based Risk Model (GERM) code was developed for the description of biophysical events from heavy ion beams at the NASA Space Radiation Laboratory (NSRL). The GERMcode calculates basic physical and biophysical quantities of high-energy protons and heavy ions that have been studied at NSRL for the purpose of simulating space radiobiological effects. For mono-energetic beams, the code evaluates the linear-energy transfer (LET), range (R), and absorption in tissue equivalent material for a given Charge (Z), Mass Number (A) and kinetic energy (E) of an ion. In addition, a set of biophysical properties are evaluated such as the Poisson distribution of ion or delta-ray hits for a specified cellular area, cell survival curves, and mutation and tumor probabilities. The GERMcode also calculates the radiation transport of the beam line for either a fixed number of user-specified depths or at multiple positions along the Bragg curve of the particle. The contributions from primary ion and nuclear secondaries are evaluated. The GERMcode accounts for the major nuclear interaction processes of importance for describing heavy ion beams, including nuclear fragmentation, elastic scattering, and knockout-cascade processes by using the quantum multiple scattering fragmentation (QMSFRG) model. The QMSFRG model has been shown to be in excellent agreement with available experimental data for nuclear fragmentation cross sections, and has been used by the GERMcode for application to thick target experiments. The GERMcode provides scientists participating in NSRL experiments with the data needed for the interpretation of their experiments, including the ability to model the beam line, the shielding of samples and sample holders, and the estimates of basic physical and biological outputs of the designed experiments. We present an overview of the GERMcode GUI, as well as providing training applications.

Kim, Myung-Hee Y.↗
NASA NTRS1983

An analysis of propulsion options for transport of lunar materials to earth orbit

This paper describes the results of analyses of space-based transportation systems for the transport of extraterrestrial materials from their point of origin on the lunar surface to final delivery point in earth orbit and transport of equipment and supplies for extraterrestrial processing to the operational site. The emphasis has been on the use of near-term (pre-year 2000) propulsion systems, such as advanced chemical (H2, O2) and nuclear-electric systems. More exotic systems (mass drivers, nuclear-thermal rockets, etc.) were also considered to evaluate the potential to be gained by use of post-year 2000 technologies. Finally, the effects of using extraterrestrial propellants (e.g., H2 from lunar polar water-ice for chemical systems) were compared to those of propulsion systems deriving all or part of their propellants from the earth.

Frisbee, R. H.↗
NASA NTRS1993

Propulsion Systems Panel deliberations

The Propulsion Systems Panel was established because of the specialized nature of many of the materials and structures technology issues related to propulsion systems. This panel was co-chaired by Carmelo Bianca, MSFC, and Bob Miner, LeRC. Because of the diverse range of missions anticipated for the Space Transportation program, three distinct propulsion system types were identified in the workshop planning process: liquid propulsion systems, solid propulsion systems and nuclear electric/nuclear thermal propulsion systems.

Bianca, Carmelo J.↗
NASA NTRS2010

Overview of the Graphical User Interface for the GERM Code (GCR Event-Based Risk Model

The descriptions of biophysical events from heavy ions are of interest in radiobiology, cancer therapy, and space exploration. The biophysical description of the passage of heavy ions in tissue and shielding materials is best described by a stochastic approach that includes both ion track structure and nuclear interactions. A new computer model called the GCR Event-based Risk Model (GERM) code was developed for the description of biophysical events from heavy ion beams at the NASA Space Radiation Laboratory (NSRL). The GERM code calculates basic physical and biophysical quantities of high-energy protons and heavy ions that have been studied at NSRL for the purpose of simulating space radiobiological effects. For mono-energetic beams, the code evaluates the linear-energy transfer (LET), range (R), and absorption in tissue equivalent material for a given Charge (Z), Mass Number (A) and kinetic energy (E) of an ion. In addition, a set of biophysical properties are evaluated such as the Poisson distribution of ion or delta-ray hits for a specified cellular area, cell survival curves, and mutation and tumor probabilities. The GERM code also calculates the radiation transport of the beam line for either a fixed number of user-specified depths or at multiple positions along the Bragg curve of the particle. The contributions from primary ion and nuclear secondaries are evaluated. The GERM code accounts for the major nuclear interaction processes of importance for describing heavy ion beams, including nuclear fragmentation, elastic scattering, and knockout-cascade processes by using the quantum multiple scattering fragmentation (QMSFRG) model. The QMSFRG model has been shown to be in excellent agreement with available experimental data for nuclear fragmentation cross sections, and has been used by the GERM code for application to thick target experiments. The GERM code provides scientists participating in NSRL experiments with the data needed for the interpretation of their experiments, including the ability to model the beam line, the shielding of samples and sample holders, and the estimates of basic physical and biological outputs of the designed experiments. We present an overview of the GERM code GUI, as well as providing training applications.

Kim, Myung-Hee↗
NASA NTRSDate not supplied

Lunar Nuclear Reactor Neutron Fluence and Gamma Dose Estimates

NASA aims to deploy a fission reactor on the lunar surface by 2030 to generate 100 kWe of power for at least 10 years without maintenance or refueling. To assess system and subsystem survivability according to those requirements, a model of the reactor pallet was created in the radiation transport code MCNP to determine the neutron fluences and gamma doses that the materials and systems would be exposed to. The model was based on the 2025 government design. The model indicated that the control drum motors, Brayton cycle engines, and pipes and valves would be exposed to neutron fluences of 1×10 15 – 1×10 16 n/cm 2 per year and gamma doses ranging from 10 to 500 Mrad per year. The electronics box housing the instrumentation and control elements is expected to receive 1×10 14 – 1×10 15 n/cm 2 per year and gamma doses in the range of 1–5 Mrad per year. These doses necessitate that the control drum motors, Brayton cycle engines, valve components, control electronics, and other components be radiation-hardened (>10 16 n/cm 2 and >10 Mrad gamma dose) or additionally shielded to survive the 10-year lunar mission.

Radiation-Hardened Materials↗
NASA NTRS1983

Heavy ion transport in the straight ahead approximation

An as yet unsolved problem in space radiation protection is the necessary relation between the external cosmic ray heavy ion fluence and the resultant environment within the spacecraft. Such a relation involves the transport of such ions through extended materials. Presented is a derivation of the solution of the transport equation for heavy ions in the straight ahead approximation for directed beam applications. An iterative scheme for the solution of the inhomogeneous integral transport equations is applied to a neon ion beam in water. The iterative scheme requires transport coefficients as input, which are determined from the available data on ion nuclear reactions. The iteration converged for the neon beam in water. Thus this iterative scheme appears to be a suitable approximation of heavy ion transport.

Wilson, J. W.↗
NASA NTRS2019

Commercialization and Human Settlement of the Moon and Cislunar Space – A Look Ahead at the Possibilities over the Next 50 Years

Over 50 years have passed since the movie 2001: A Space Odyssey debuted in April 1968. In the film, Dr. Heywood Floyd flies to a large artificial gravity space station orbiting Earth aboard a commercial space plane. He then embarks on a commuter flight to the Moon arriving there 25hours later. Today, on the 50th anniversary of the Apollo 11 lunar landing, the images portrayed in 2001 still remain well beyond our capabilities. This paper examines key technologies and systems (in-situ resource utilization, fission power, advanced chemical and nuclear propulsion),and orbiting infrastructure elements (providing a propellant depot and cargo transfer function),that could be developed by NASA and the private sector in future decades allowing the operational capabilities presented in 2001 to be achieved, albeit on a more spartan scale. Lunar derived propellants (LDPs) will be essential to reducing the launch mass requirements from Earth and developing a reusable lunar transportation system (LTS) that can allow initial outposts to evolve into settlements supporting a variety of commercial activities like in-situ propellant production. Deposits of icy regolith found within permanently shadowed craters at the lunar pole scan supply the feedstock material to produce liquid oxygen (LO2) and hydrogen (LH2) propellan tneeded by surface-based lunar landing vehicles (LLVs) using chemical rocket engines. Along the Moon's nearside equatorial corridor, iron oxide-rich volcanic glass beads from vast pyroclasticdeposits, together with mare regolith, can provide the materials to produce lunar-derived LO2plus other important solar wind implanted (SWI) volatiles, including H2 and helium-3. Mega watt classfission power systems will be essential for providing continuous "24/7" power to LLVs will provide cargo and passenger "orbit-to-surface" access and willalso be used to transport LDP to Space Transportation Nodes (STNs) located in lunar polar(LPO) and equatorial orbits (LLO). Spaced-based, reusable lunar transfer vehicles (LTVs),operating between STNs in low Earth orbit (LEO), LLO, and LPO, and able to refuel with LDPs,can offer unique mission capabilities including short transit time crewed cargo transports. Even acommuter shuttle service similar to that portrayed in 2001 appears possible, allowing 1-way trip times to and from the Moon as short as 24 hours. The performance of LTVs using both RL10B-2chemical rockets, and a variant of the nuclear thermal rocket (NTR), the LO2-Augmented NTR(LANTR), are examined and compared. The bipropellant LANTR engine utilizes its divergent nozzle section as an afterburner into which oxygen is injected and supersonically combusted with reactor-heated hydrogen emerging from the engine's sonic throat. If only 1% of the LDP obtained from icy regolith, volcanic glass, and SWI volatile deposits were available for use in lunar orbit,such a supply could support routine commuter flights to the Moon for many thousands of years!This paper provides a look ahead at what might be possible in the not too distant future,quantifies the operational characteristics of key in-space and surface technologies and systems,and provides conceptual designs for the various architectural elements discussed.

Borowski, Stanley K.↗
NASA NTRS1987

The effect of neutrino transport on the collapse of iron stellar cores

A multigroup flux-limited diffusion approximation to neutrino transport, correct to first order in material velocities, is described. The role of neutrino-electron scattering in determining core deleptonization is studied using a modified Fokker-Planck approximation in which adjacent neutrino energy groups are coupled. The moderate deleptonizaton obtained during infall restricts homologous core masses to less than 0.8 solar mass. With 0.6-0.8 solar mass of outer core to traverse, nuclear dissociation alone stalls the shock waves produced at core bounce. In addition, neutrino energy losses remove at least another 4 x 10 to the 51st ergs. In no case is matter ejected promptly as a direct result of the initial shock wave.

Myra, E. S.↗
NASA NTRS1999

Shielding from Solar Particle Event Exposures in Deep Space

The physical composition and intensities of solar particle event exposures or sensitive astronaut tissues are examined under conditions approximating an astronaut in deep space. Response functions for conversion of particle fluence into dose and dose equivalent averaged over organ tissue, are used to establish significant fluence levels and the expected dose and dose rates of the most important events from past observations. The BRYNTRN transport code is used to evaluate the local environment experienced by sensitive tissues and used to evaluate bioresponse models developed for use in tactical nuclear warfare. The present results will help to the biophysical aspects of such exposure in the assessment of RBE and dose rate effects and their impact on design of protection systems for the astronauts. The use of polymers as shielding material in place of an equal mass of aluminum would prowide a large safety factor without increasing the vehicle mass. This safety factor is sufficient to provide adequate protection if a factor of two larger event than has ever been observed in fact occurs during the mission.

Wilson, John W.↗
NASA NTRS2019

Commercial and Human Settlement of the Moon and Cislunar Space – A Look Ahead at the Possibilities over the Next 50 Years

Over 50 years have passed since the movie 2001: A Space Odyssey debuted in April 1968. In the film, Dr. Heywood Floyd flies to a large artificial gravity space station orbiting Earth aboard a commercial space plane. He then embarks on a commuter flight to the Moon arriving there 25 hours later. Today, on the 50th anniversary of the Apollo 11 lunar landing, the images portrayed in 2001 still remain well beyond our capabilities. This paper examines key technologies and systems (in-situ resource utilization, fission power, advanced chemical and nuclear propulsion), and orbiting infrastructure elements (providing a propellant depot and cargo transfer function), that could be developed by NASA and the private sector in future decades allowing the operational capabilities presented in 2001 to be achieved, albeit on a more spartan scale. Lunar-derived propellants (LDPs) will be essential to reducing the launch mass requirements from Earth and developing a reusable lunar transportation system (LTS) that can allow initial outposts to evolve into settlements supporting a variety of commercial activities like in-situ propellant production. Deposits of icy regolith found within permanently shadowed craters at the lunar poles can supply the feedstock material to produce liquid oxygen (LO2) and hydrogen (LH2) propellant needed by surface-based lunar landing vehicles (LLVs) using chemical rocket engines. Along the Moon’s nearside equatorial corridor, iron oxide-rich volcanic glass beads from vast pyroclastic deposits, together with mare regolith, can provide the materials to produce lunar-derived LO2 plus other important solar wind implanted (SWI) volatiles, including H2 and helium-3. Megawatt-class fission power systems will be essential for providing continuous “24/7” power to processing plants, evolving human settlements, and other commercial activities that develop on the Moon and in orbit. Reusable LLVs will provide cargo and passenger “orbit-to-surface” access and will also be used to transport LDP to Space Transportation Nodes (STNs) located in lunar polar (LPO) and equatorial orbits (LLO). Spaced-based, reusable lunar transfer vehicles (LTVs), operating between STNs in low Earth orbit (LEO), LLO, and LPO, and able to refuel with LDPs, can offer unique mission capabilities including short transit time crewed cargo transports. Even a commuter shuttle service similar to that portrayed in 2001 appears possible, allowing 1-way trip times to and from the Moon as short as 24 hours. The performance of LTVs using both RL10B-2 chemical rockets, and a variant of the nuclear thermal rocket (NTR), the LO2-Augmented NTR (LANTR), are examined and compared. The bipropellant LANTR engine utilizes its divergent nozzle section as an afterburner into which oxygen is injected and supersonically combusted with reactor-heated hydrogen emerging from the engine’s sonic throat. If only 1% of the LDP obtained from icy regolith, volcanic glass, and SWI volatile deposits were available for use in lunar orbit, such a supply could support routine commuter flights to the Moon for many thousands of years! This paper provides a look ahead at what might be possible in the not too distant future, quantifies the operational characteristics of key in-space and surface technologies and systems, and provides conceptual designs for the various architectural elements discussed.

Borowski, Stanley K.↗
NASA NTRS1972

Study, selection, and preparation of solid cationic conductors

Crystal chemical principles and transport theory were used to predict structures and specific compounds which might find application as solid electrolytes in rechargeable high energy and high power density batteries operating at temperatures less than 200 C. More than twenty compounds were synthesized or obtained and screened by nuclear magnetic resonance and conductivity. Many were densified by sintering or hot pressing. Encouraging results were obtained for nine of these materials but none have yet been good ionic conductors at low temperature.

Roth, W. L.↗
NASA NTRS1974

Study, selection, and preparation of solid cationic conductors

Crystal chemical principles and transport theory have been used to predict structures and specific compounds which might find application as solid electrolytes in rechargeable high energy and high power density batteries operating at temperatures less than 200 C. Structures with 1-, 2-, and 3-dimensional channels were synthesized and screened by nuclear magnetic resonance, dielectric loss, and conductivity. There is significant conductivity at room temperature in some of the materials but none attain a level that is comparable to beta-alumina. Microwave and fast pulse methods were developed to measure conductivity in powders and in small crystals.

Roth, W. L.↗
NASA NTRS2018

Radiation Transport and Shielding Challenges at NASA Marshall Space Flight Center

Several unique radiation transport and shielding challenges for various spacecraft and ground test facilities have recently been explored at NASA Marshall Space Flight Center (MSFC). Many radiation transport methods and code packages have been utilized during this effort, and some additional analytical tools have been developed to support this work. This includes the development of a nuclear thermal propulsion stage, in which radiation damage to hardware, radiation heating, and crew dose must be assessed for a large spacecraft. Radiation shielding for such a stage must be optimized to minimize weight, and additional dose consequences are expected from cosmic sources. Development of a nuclear engine requires ground test facilities, which themselves require significant development effort that includes deep-penetration shielding analysis for facility design and site selection. Additional radiation transport analysis has been performed in support of a notional lander mission to Europa, the icy moon of Jupiter. The radiation burden to spacecraft has been analyzed, and charged particle radiation transport methods have been utilized to apply correct doses to material samples in ground test facilities.

Caffrey, Jarvis A.↗
NASA NTRS1996

Light ion components of the galactic cosmic rays: Nuclear interactions and transport theory

Light nuclei are present in the primary galactic cosmic rays (GCR) and are produced in thick targets due to projectile or target fragmentation from both nucleon and heavy induced reactions. In the primary GCR, He-4 is the most abundant nucleus after H-1. However, there are also a substantial fluxes of H-2 and He-3. In this paper we describe theoretical models based on quantum multiple scattering theory for the description of light ion nuclear interactions. The energy dependence of the light ion fragmentation cross section is considered with comparisons of inclusive yields and secondary momentum distributions to experiments described. We also analyze the importance of a fast component of lights ions from proton and neutron induced target fragementation. These theoretical models have been incorporated into the cosmic ray transport code HZETRN and will be used to analyze the role of shielding materials in modulating the production and the energy spectrum of light ions.

Cucinotta, F. A.↗
NASA NTRS1999

Initial Test Firing Results for Solid CO/GOX Cryogenic Hybrid Rocket Engine for Mars ISRU Propulsion Applications

ORBITEC is developing methods for producing, testing, and utilizing Mars-based ISRU fuel/oxidizer combinations to support low cost, planetary surface and flight propulsion and power systems. When humans explore Mars we will need to use in situ resources that are available, such as: energy (solar); gases or liquids for life support, ground transportation, and flight to and from other surface locations and Earth; and materials for shielding and building habitats and infrastructure. Probably the easiest use of Martian resources to reduce the cost of human exploration activities is the use of the carbon and oxygen readily available from the CO2 in the Mars atmosphere. ORBITEC has conducted preliminary R&D that will eventually allow us to reliably use these resources. ORBITEC is focusing on the innovative use of solid CO as a fuel. A new advanced cryogenic hybrid rocket propulsion system is suggested that will offer advantages over LCO/LOX propulsion, making it the best option for a Mars sample return vehicle and other flight vehicles. This technology could also greatly support logistics and base operations by providing a reliable and simple way to store solar or nuclear generated energy in the form of chemical energy that can be used for ground transportation (rovers/land vehicles) and planetary surface power generators. This paper describes the overall concept and the test results of the first ever solid carbon monoxide/oxygen rocket engine firing.

Rice, Eric E.↗
NASA NTRS1989

Bars within bars - A mechanism for fuelling active galactic nuclei

A mechanism, applicable to AGN and nuclear starburst galaxies in which there is accretion onto a supermassive black hole (SBH), is proposed which brings in gas from large to small scales by successive dynamical instabilities. On the large scale, a stellar bar sweeps the interstellar medium into a gaseous disk a few hundred pc in radius. Under certain conditions, this disk can become unstable again, allowing material to flow inwards until turbulent viscous processes control angular-momentum transport. This flow pattern may feed viscosity-driven accretion flows around an SBH or lead to the formation of an SBH if none was present initially.

Shlosman, Isaac↗