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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 613 records · Page 34
All sourcesNASA NTRSDOE OSTI
NASA NTRS1990

The effect of latent heat release on synoptic-to-planetary wave interactions and its implication for satellite observations: Theoretical modeling

The project objectives are to develop process models to investigate the interaction of planetary and synoptic-scale waves including the effects of latent heat release (precipitation), nonlinear dynamics, physical and boundary-layer processes, and large-scale topography; to determine the importance of latent heat release for temporal variability and time-mean behavior of planetary and synoptic-scale waves; to compare the model results with available observations of planetary and synoptic wave variability; and to assess the implications of the results for monitoring precipitation in oceanic-storm tracks by satellite observing systems. Researchers have utilized two different models for this project: a two-level quasi-geostrophic model to study intraseasonal variability, anomalous circulations and the seasonal cycle, and a 10-level, multi-wave primitive equation model to validate the two-level Q-G model and examine effects of convection, surface processes, and spherical geometry. It explicitly resolves several planetary and synoptic waves and includes specific humidity (as a predicted variable), moist convection, and large-scale precipitation. In the past year researchers have concentrated on experiments with the multi-level primitive equation model. The dynamical part of that model is similar to the spectral model used by the National Meteorological Center for medium-range forecasts. The model includes parameterizations of large-scale condensation and moist convection. To test the validity of results regarding the influence of convective precipitation, researchers can use either one of two different convective schemes in the model, a Kuo convective scheme or a modified Arakawa-Schubert scheme which includes downdrafts. By choosing one or the other scheme, they can evaluate the impact of the convective parameterization on the circulation. In the past year researchers performed a variety of initial-value experiments with the primitive-equation model. Using initial conditions typical of climatological winter conditions, they examined the behavior of synoptic and planetary waves growing in moist and dry environments. Surface conditions were representative of a zonally averaged ocean. They found that moist convection associated with baroclinic wave development was confined to the subtropics.

Branscome, Lee E.↗
NASA NTRS1992

The Extended Mission Rover (EMR)

A key component in ensuring America's status as a leader in the global community is its active pursuit of space exploration. On the twentieth anniversary of Apollo 11, President George Bush challenged the nation to place a man on the moon permanently and to conduct human exploration of Mars in the 21st century. The students of the FAMU/FSU College of Engineering hope to make a significant contribution to this challenge, America's Space Exploration Initiative (SEI), with their participation in the NASA/USRA Advanced Design Program. The project selected by the 1991/1992 Aerospace Design group is the design of an Extended Mission Rover (EMR) for use on the lunar surface. This vehicle will serve as a mobile base to provide future astronauts with a 'shirt-sleeve' living and working environment. Some of the proposed missions are planetary surface exploration, construction and maintenance, hardware setup, and in situ resource experimentation. This vehicle will be put into use in the 2010-2030 time frame.

Shields, W.↗
NASA NTRS2000

Progress in Fire Detection and Suppression Technology for Future Space Missions

Fire intervention technology (detection and suppression) is a critical part of the strategy of spacecraft fire safety. This paper reviews the status, trends, and issues in fire intervention, particularly the technology applied to the protection of the International Space Station and future missions beyond Earth orbit. An important contribution to improvements in spacecraft fire safety is the understanding of the behavior of fires in the non-convective (microgravity) environment of Earth-orbiting and planetary-transit spacecraft. A key finding is the strong influence of ventilation flow on flame characteristics, flammability limits and flame suppression in microgravity. Knowledge of these flow effects will aid the development of effective processes for fire response and technology for fire suppression.

Friedman, Robert↗
NASA NTRS2001

Laser Altimetry for Earth and Planetary Science

Laser altimeters are presently operating on spacecraft at Mars (MOLA), at the asteroid 433 Eros (NLR), and an earlier system operated at the Moon (Clementine) several years ago. These systems have all advanced our understanding of the evolution of the primary body and several more laser altimeter systems will be launched in the next several years around Earth and other planets to address a wide range of scientific problems. Laser technology for precision altimetry and atmospheric lidar is still in its infancy but the promise of the technology and its demonstrated results already show that laser altimetry/lidar will play an important role in future space observations. To date, lasers have mapped the Moon, Mars, and an asteroid but in a short while they will help measure the planetary librations of Mercury, the tidal distortions of Europa, and tree heights, upper atmosphere winds and the icecaps of planet Earth. Major areas of interest for the immediate future are the development of long-life lasers that can withstand the rigors of long planetary missions in extreme thermal and radiation environments and continue to operate successfully for many years.

Smith, David E.↗
NASA NTRS2004

Exploration EVA System

In January 2004, the President announced a new Vision for Space Exploration. NASA's Office of Exploration Systems has identified Extravehicular Activity (EVA) as a critical capability for supporting the Vision for Space Exploration. EVA is required for all phases of the Vision, both in-space and planetary. Supporting the human outside the protective environment of the vehicle or habitat and allow ing him/her to perform efficient and effective work requires an integrated EVA "System of systems." The EVA System includes EVA suits, airlocks, tools and mobility aids, and human rovers. At the core of the EVA System is the highly technical EVA suit, which is comprised mainly of a life support system and a pressure/environmental protection garment. The EVA suit, in essence, is a miniature spacecraft, which combines together many different sub-systems such as life support, power, communications, avionics, robotics, pressure systems and thermal systems, into a single autonomous unit. Development of a new EVA suit requires technology advancements similar to those required in the development of a new space vehicle. A majority of the technologies necessary to develop advanced EVA systems are currently at a low Technology Readiness Level of 1-3. This is particularly true for the long-pole technologies of the life support system.

Kearney, Lara↗
NASA NTRS2005

Robotic Technologies for Surveying Habitats and Seeking Evidence of Life: Results from the 2004 Field Experiments of the "Life in the Atacama" Project

The Chilean Atacama Desert is the most arid region on Earth and in several ways analogous to Mars. Evidence suggests that the interior of the Atacama is lifeless, yet where the desert meets the Pacific coastal range dessication-tolerant microorganisms are known to exist. The gradient of biodiversity and habitats in the Atacama's subregions remain unexplored and are the focus of the Life in the Atacama project. Our field investigation attempts to bring further scientific understanding of the Atacama as a habitat for life through the creation of robotic astrobiology. This involves capabilities for autonomously traversing hundreds of kilometers while deploying sensors to survey the varying geologic and biologic properties of the environment, Fig. 1. Our goal is to make genuine discoveries about the limits of life on Earth and to generate knowledge about life in extreme environments that can be applied to future planetary missions. Through these experiments we also hope to develop and practice the methods by which a rover might best be employed to survey desert terrain in search of the habitats in which life can survive, or may have in the past.

Wettergreen, D.↗
NASA NTRS2003

Visualization experiences and issues in Deep Space Exploration

The panelists will discuss their experiences in collecting data in deep space, transmitting it to Earth, processing and visualizing it here, and using the visualization to drive the continued mission. This closes the loop, making missions more responsive to their environment, particularly in-situ operations on planetary surfaces and within planetary atmospheres.

visualization↗
NASA NTRS2007

Balloon Design Software

PlanetaryBalloon Version 5.0 is a software package for the design of meridionally lobed planetary balloons. It operates in a Windows environment, and programming was done in Visual Basic 6. By including the effects of circular lobes with load tapes, skin mass, hoop and meridional stress, and elasticity in the structural elements, a more accurate balloon shape of practical construction can be determined as well as the room-temperature cut pattern for the gore shapes. The computer algorithm is formulated for sizing meridionally lobed balloons for any generalized atmosphere or planet. This also covers zero-pressure, over-pressure, and super-pressure balloons. Low circumferential loads with meridionally reinforced load tapes will produce shapes close to what are known as the "natural shape." The software allows for the design of constant angle, constant radius, or constant hoop stress balloons. It uses the desired payload capacity for given atmospheric conditions and determines the required volume, allowing users to design exactly to their requirements. The formulations are generalized to use any lift gas (or mixture of gases), any atmosphere, or any planet as described by the local acceleration of gravity. PlanetaryBalloon software has a comprehensive user manual that covers features ranging from, but not limited to, buoyancy and super-pressure, convenient design equations, shape formulation, and orthotropic stress/strain.

Farley, Rodger↗
NASA NTRS2005

Dusty-Plasma Particle Accelerator

A dusty-plasma apparatus is being investigated as means of accelerating nanometer- and micrometer-sized particles. Applications for the dusty-plasma particle accelerators fall into two classes: Simulation of a variety of rapidly moving dust particles and micrometeoroids in outer-space environments that include micrometeoroid streams, comet tails, planetary rings, and nebulae and Deposition or implantation of nanoparticles on substrates for diverse industrial purposes that could include hardening, increasing thermal insulation, altering optical properties, and/or increasing permittivities of substrate materials. Relative to prior apparatuses used for similar applications, dusty-plasma particle accelerators offer such potential advantages as smaller size, lower cost, less complexity, and increased particle flux densities. A dusty-plasma particle accelerator exploits the fact that an isolated particle immersed in plasma acquires a net electric charge that depends on the relative mobilities of electrons and ions. Typically, a particle that is immersed in a low-temperature, partially ionized gas, wherein the average kinetic energy of electrons exceeds that of ions, causes the particle to become negatively charged. The particle can then be accelerated by applying an appropriate electric field. A dusty-plasma particle accelerator (see figure) includes a plasma source such as a radio-frequency induction discharge apparatus containing (1) a shallow cup with a biasable electrode to hold the particles to be accelerated and (2) a holder for the substrate on which the particles are to impinge. Depending on the specific design, a pair of electrostatic-acceleration grids between the substrate and discharge plasma can be used to both collimate and further accelerate particles exiting the particle holder. Once exposed to the discharge plasma, the particles in the cup quickly acquire a negative charge. Application of a negative voltage pulse to the biasable electrode results in the initiation of a low-current, high-voltage cathode spot. Plasma pressure associated with the cathode spot as well as the large voltage drop at the cathode spot accelerates the charged particles toward the substrate. The ultimate kinetic energy attained by particles exiting the particle holder depends in part on the magnitude of the cathode spot sheath potential difference, which is proportional to the magnitude of the voltage pulse, and the on the electric charge on the dust. The magnitude of the voltage pulse can be controlled directly, whereas the particle s electric charge can be controlled indirectly by controlling the operating parameters of the plasma apparatus.

Foster, John E.↗
NASA NTRS2011

Tomographic Reconstruction of Mercury's Exosphere from MESSENGER Flyby Data

The exosphere of Mercury is among the best-studied examples of a common type of atmosphere, a surface-bounded exosphere. Mercury's exosphere was probed in 2008-2009 with Ultraviolet and Visible Spectrometer (UVVS) measurements obtained during three planetary flybys by the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft [1-3]. The measurements detailed the distribution of two previously known metallic constituents of Mercury's exosphere, Na and Ca, and indicated the presence in the gas phase of yet another metallic species, Mg. Such measurements can answer fundamental scientific questions regarding the relative importance of possible source and loss processes for exospheric species ejected from a surface boundary [4]. The trajectory of MESSENGER during the last of its three flybys provided the best spatial coverage prior to orbit insertion. The measurements by MESSENGER of Na, Ca, and Mg during the third flyby have been analyzed with a novel tomographic method. This approach maximizes the amount of information that can be extracted from line-of-sight measurements because it yields three-dimensional distributions of neutrals consistent with the data.

Killen, Rosemary M.↗
NASA NTRS2018

New Efforts to Update NASA's Global Reference Atmospheric Models (GRAM)

NASA is at the forefront of planetary exploration. The inability to test planetary space-craft in the flight environment prior to a mission requires engineers to rely on ground-based testing and models of the vehicle and expected environments. One of the most widely used engineering models of the atmosphere for many NASA projects is the Global Reference Atmospheric Model (GRAM) developed by the NASA Marshall Space Flight Center (MSFC). Over the past decade GRAM upgrades and maintenance have depended on inconsistent and waning project-specific support. Recently, the NASA Science Mission Directorate (SMD) has agreed to provide funding support in Fiscal Year 2018 and 2019 to upgrade the GRAMs.

Justh, H. L.↗
NASA NTRS2019

Effect of Phenolic Matrix Microcracking on the Structural Response of a 3-D Woven Thermal Protection System

The effect of microcracking in the phenolic matrix of a three-dimensional woven thermal protection system (TPS) and the resulting material stiffness reduction was studied via a comparison of finite element analysis results from a linear analysis and an iterative linear analysis. A TPS is necessary to protect space vehicles from the aerodynamic heating of planetary entry. The Heatshield for Extreme Entry Environment Technology (HEEET) project has developed a TPS for use in high heat-flux and pressure missions. The material is a dual-layer continuous dry weave, which is then infiltrated with a low-density phenolic resin matrix to form a rigid ablator. The phenolic resin matrix does not have structural load transfer requirements, and testing has shown that the phenolic resin can fully satisfy thermal requirements when the matrix contains microcracks. Due to high stresses in the through-the-thickness direction of the material, phenolic microcracks may form in the matrix material, which would result in a reduction of stiffness. An exploratory study was conducted to determine if reduction in material stiffness would change the load paths and/or decrease the structural margins. A comparison was performed between a linear finite element analysis that did not take into account phenolic microcracking and an iterative linear finite element analysis that accounted for propagation of phenolic microcracking. Four subcases using varying assumptions were analyzed and the results indicate that the assumed strength at which the phenolic microcracking propagates was the critical parameter for determining the extent of microcracking in the phenolic matrix. Phenolic microcracking does not have an adverse effect on the structural response of the test article and is not a critical failure.

Langston, Sarah L.↗
NASA NTRSDate not supplied

Plants in Space and Space Crop Production

As astronauts venture farther from Earth, and for longer periods, food will become increasingly critical. Crop production can supplement a packaged diet to provide additional nutrients and dietary variety for astronauts, and plants may also provide psychological and environmental benefits. Several unique challenges exist for growth of plants in microgravity and on other planetary surfaces. Terrestrial tests in analog space environments contribute to our knowledge, while testing on the International Space Station allows us to better understand the impacts of gravity and spaceflight on crop growth and the importance of plants to astronauts living and working away from our blue home planet.

Gioia Massa↗
NASA NTRS2020

NASA Ames Thermophysics Ground Test Facilities Supporting Future Planetary Atmospheric Entry

A review of the current facility capabilities for testing Thermal Protection Systems and quantifying their entry environments at NASA Ames Research Center is presented based on the expected targets of interest to the Planetary Science and Astrobiology communities. While the operational capabilities of these facilities are generally considered sufficient for supporting future missions to targets of interest, expanded ground test capabilities such as larger sample sizes, flight-relevant gas mixtures, dusty environments, and flight-relevant shear/pressure combinations would reduce future entry vehicle design uncertainties and applied margins. These reduced uncertainties may translate into reduced entry vehicle masses, increased robustness, and decreased operational risks during entry phases for science missions. Expanded ground test capabilities would also offer the ability to study material failure modes in environments even more representative of flight than are currently achievable. A list of desired future test capabilities is presented along with suggestions of possible methods of achieving each. The main recommendation of this paper is the undertaking of a detailed study of the benefits and associated costs of each of these expanded capabilities to determine the best future path.

arc jet↗
NASA NTRS1989

Planetary protection and back contamination control for a Mars rover sample return mission

A commitment to avoid the harmful contamination of outer space and avoid adverse changes in the environment of the earth has been long reflected in NASA's Planetary Protection policy. Working under guidelines developed by the Committee on Space Research (COSPAR), NASA has implemented the policy in an interactive process that has included the recommendations of the U.S. National Academy of Sciences. Measures taken to prevent the contamination of earth during the Apollo missions were perhaps the most visible manifestations of this policy, and provided numerous lessons for future sample return opportunities. This paper presents the current status of planetary protection policy within NASA, and a prospectus on how planetary protection issues might be addressed in relation to a Mars Rover Sample Return mission.

Rummel, John D.↗
NASA NTRS1999

Laboratory Simulations of Martian and Venusian Aeolian Processes

With the flyby of the Neptune system by Voyager, the preliminary exploration of the Solar System was accomplished. Data have been returned for all major planets and satellites except the Pluto system. Results show that the surfaces of terrestrial planets and satellites have been subjected to a wide variety of geological processes. On solid- surface planetary objects having an atmosphere, aeolian processes are important in modifying their surfaces through the redistribution of fine-grained material by the wind. Bedrock may be eroded to produce particles and the particles transported by wind for deposition in other areas. This process operates on Earth today and is evident throughout the geological record. Aeolian processes also occur on Mars, Venus, and possibly Titan and Triton, both of which are outer planet satellites that have atmospheres. Mariner 9 and Viking results show abundant wind-related landforms on Mars, including dune fields and yardangs (wind-eroded hills). On Venus, measurements made by the Soviet Venera and Vega spacecraft and extrapolations from the Pioneer Venus atmospheric probes show that surface winds are capable of transporting particulate materials and suggest that aeolian processes may operate on that planet as well. Magellan radar images of Venus show abundant wind streaks in some areas, as well as dune fields and a zone of possible yardangs. The study of planetary aeolian processes must take into account diverse environments, from the cold, low-density atmosphere of Mars to the extremely hot, high- density Venusian atmosphere. Factors such as threshold wind speeds (minimum wind velocity needed to move particles), rates of erosion and deposition, trajectories of windblown particles, and aeolian flow fields over various landforms are all important aspects of the problem. In addition, study of aeolian terrains on Earth using data analogous to planetary data-collection systems is critical to the interpretation of spacecraft information and places constraints on results from numerical models and laboratory simulations.

Greeley, Ronald↗
NASA NTRSDate not supplied

Using Earth-based Operational Field Tests as High-Fidelity Analogs for Planetary Surface Exploration

NASA is preparing to land the first woman and first person of color on the Moon within the next decade and establish a permanent sustainable human presence before sending humans onto Mars. To ensure the success of these missions, NASA has performed operational testing in terrestrial, aquatic, and laboratory analog environments that simulate Lunar and Martian environmental characteristics to evaluate exploration concepts of operations (ConOps), engineering design requirements, science support needs, mission operations techniques, and crew training. Terrestrial analogs include Desert Research and Technology Studies (D-RATS), Biologic Analog Science Associated with Lava Terrains (BASALT), and Next Space Technologies for Exploration Partnerships (NextSTEP)Habitat Ground Testing. Aquatic analogs include NASA Extreme Environment Mission Operations (NEEMO) and Pavilion Lake Research Project (PLRP).Laboratory analogs include the Neutral Buoyancy Laboratory (NBL), Active Response Gravity Offload System(ARGOS), rock yards, and virtual and hybrid reality simulation environments. While no single Earth-based analog environment is perfect for simulating all characteristics of other planetary surfaces, testing across multiple locations leverages the strengths of each to provide an integrated understanding of how to best conduct real spaceflight surface exploration missions.

B A Janoiko↗
NASA NTRS2017

Recent Progress in Laboratory Astrophysics and Astrochemistry Achieved with the COSmIC Facility

We describe the characteristics and the capabilities of the laboratory facility, COSmIC, that was developed at NASA Ames to generate, process and analyze interstellar, circumstellar and planetary analogs in the laboratory. COSmIC stands for "Cosmic Simulation Chamber" and is dedicated to the study of neutral and ionized molecules and nanoparticles under the low temperature and high vacuum conditions that are required to simulate various space environments such as diffuse interstellar clouds, circumstellar outflows and planetary atmospheres. COSmIC integrates a variety of state-of-the-art instruments that allow recreating simulated space conditions to generate, process and monitor cosmic analogs in the laboratory. The COSmIC experimental setup is composed of a Pulsed Discharge Nozzle (PDN) expansion, that generates a plasma in the stream of a free supersonic jet expansion, coupled to high-sensitivity, complementary in situ diagnostics: cavity ring down spectroscopy (CRDS) and laser induced fluorescence (LIF) systems for photonic detection, and Reflectron Time-Of-Flight Mass Spectrometer (ReTOF-MS) for mass detection. Recent results obtained using COSmIC will be highlighted. In particular, the progress that has been achieved in the domain of the diffuse interstellar bands (DIBs) and in monitoring, in the laboratory, the formation of circumstellar dust grains and planetary atmosphere aerosols from their gas-phase molecular precursors. Plans for future laboratory experiments on interstellar and planetary molecules and grains will also be addressed, as well as the implications of the studies underway for astronomical observations and past and future space mission data analysis.

Salama, Farid↗