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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 901 records · Page 50

Observations of Shock Diffusion and Interactions in Supersonic Freestreams with Counterflowing Jets

One of the technical challenges in long-duration space exploration and interplanetary missions is controlled entry and re-entry into planetary and Earth atmospheres, which requires the dissipation of considerable kinetic energy as the spacecraft decelerates and penetrates the atmosphere. Efficient heat load management of stagnation points and acreage heating remains a technological challenge and poses significant risk, particularly for human missions. An innovative approach using active flow control concept is proposed to significantly modify the external flow field about the spacecraft in planetary atmospheric entry and re-entry in order to mitigate the harsh aerothermal environments, and significantly weaken and disperse the shock-wave system to reduce aerothermal loads and wave drag, as well as improving aerodynamic performance. To explore the potential benefits of this approach, we conducted fundamental experiments in a trisonic blow down wind tunnel to investigate the effects of counterflowing sonic and supersonic jets against supersonic freestreams to gain a better understanding of the flow physics of the interactions of the opposing flows and the resulting shock structure.

Daso, Endwell O.↗

PDS Lunar Data Node Restoration of Apollo In-Situ Surface Data

The Apollo missions between 1969 and 1972 deployed scientific instruments on the Moon's surface which made in-situ measurements of the lunar environment. Apollo II had the short-term Early Apollo Surface Experiments Package (EASEP) and Apollos 12, 14, 15, 16, and 17 each set up an Apollo Lunar Surface Experiments Package (ALSEP). Each ALSEP package contained a different suite of instruments which took measurements and radioed the results back to Earth over periods from 5 to 7 years until they were turned off on 30 September 1977. To this day the ALSEP data remain the only long-term in-situ information on the Moon's surface environment. The Lunar Data Node (LDN) has been formed under the auspices of the Planetary Data System (PDS) Geosciences Node to put relevant, scientifically important Apollo data into accessible digital form for use by researchers and mission planners. We will report on progress made since last year and plans for future data restorations.

Williams, David R.↗

Metabolic Costs and Biomechanics of Inclined Ambulation and Exploration Tasks in a Planetary Suit

Observations from Apollo lunar surface extravehicular activities (EVAs) and a few studies conducted in partial-gravity simulation environments have helped us understand suited human performance in reduced-gravity environments. The Constellation Program EVA Systems Project Office initiated a series of tests aimed at increasing our understanding of human performance and suit kinematics under various simulated lunar EVA conditions, including matched unsuited controls, to identify the specific metabolic costs and biomechanics of the prototype Mark III Advanced Spacesuit Technology Demonstrator. A primary goal of the series is to provide evidence-based recommendations for suit mass, center of gravity, pressure, and suit kinematic constraints that optimize human performance in partial-gravity environments. Results will be combined with studies in other lunar analogs to evaluate the effectiveness and limitations of these environments. As our understanding of suited human performance matures, different combinations of variables can be evaluated to determine whether significant interactions exist between parameters. This report provides an overview of key findings of Integrated Suit Test (IST)-2. As future tests are completed, focusing on other suit factors, analog environments, or different suits, study results will be combined and reevaluated. The series of tests comprising IST-2 was conducted from June 13, 2007 through October 24, 2007.

Aerospace environments↗

Radiation Tests of Highly Scaled, High-Density, Commercial, Nonvolatile NAND Flash Memories - Update 2012

The space radiation environment poses a certain risk to all electronic components on Earth-orbiting and planetary mission spacecraft. In recent years, there has been increased interest in the use of high-density, commercial, nonvolatile flash memories in space because of ever-increasing data volumes and strict power requirements. They are used in a wide variety of spacecraft subsystems. At one end of the spectrum, flash memories are used to store small amounts of mission-critical data such as boot code or configuration files and, at the other end, they are used to construct multi-gigabyte data recorders that record mission science data. This report examines single-event effect (SEE) and total ionizing dose (TID) response in single-level cell (SLC) 32-Gb, multi-level cell (MLC) 64-Gb, and Triple-level (TLC) 64-Gb NAND flash memories manufactured by Micron Technology with feature size of 25 nm.

Irom, Farokh↗

Optimization of a Hot Structure Aeroshell and Nose Cap for Mars Atmospheric Entry

The National Aeronautics and Space Administration (NASA) is preparing to send humans beyond Low Earth Orbit and eventually to the surface of Mars. As part of the Evolvable Mars Campaign, different vehicle configurations are being designed and considered for delivering large payloads to the surface of Mars. Weight and packing volume are driving factors in the vehicle design, and the thermal protection system (TPS) for planetary entry is a technology area which can offer potential weight and volume savings. The feasibility and potential benefits of a ceramic matrix composite hot structure concept for different vehicle configurations are explored in this paper, including the nose cap for a Hypersonic Inflatable Aerodynamic Decelerator (HIAD) and an aeroshell for a mid lift-to-drag (Mid L/D) concept. The TPS of a planetary entry vehicle is a critical component required to survive the severe aerodynamic heating environment during atmospheric en- try. The current state-of-the-art is an ablative material to protect the vehicle from the heat load. The ablator is bonded to an underlying structure, which carries the mechanical loads associated with entry. The alternative hot structure design utilizes an advanced carbon-carbon material system on the outer surface of the vehicle, which is exposed to the severe heating and acts as a load carrying structure. The preliminary design using the hot structure concept and the ablative concept is determined for the spherical nose cap of the HIAD entry vehicle and the aeroshell of the Mid L/D entry vehicle. The results of the study indicate that the use of hot structures for both vehicle concepts leads to a feasible design with potential weight and volume savings benefits over current state-of-the-art TPS technology that could enable future missions.

Langston, Sarah L.↗

Science Goals and Mission Concept for the Future Exploration of Titan and Enceladus

Saturn׳s moons, Titan and Enceladus, are two of the Solar System׳s most enigmatic bodies and are prime targets for future space exploration. Titan provides an analogue for many processes relevant to the Earth, more generally to outer Solar System bodies, and a growing host of newly discovered icy exoplanets. Processes represented include atmospheric dynamics, complex organic chemistry, meteorological cycles (with methane as a working fluid), astrobiology, surface liquids and lakes, geology, fluvial and aeolian erosion, and interactions with an external plasma environment. In addition, exploring Enceladus over multiple targeted flybys will give us a unique opportunity to further study the most active icy moon in our Solar System as revealed by Cassini and to analyse in situ its active plume with highly capable instrumentation addressing its complex chemistry and dynamics. Enceladus׳ plume likely represents the most accessible samples from an extra-terrestrial liquid water environment in the Solar system, which has far reaching implications for many areas of planetary and biological science. Titan with its massive atmosphere and Enceladus with its active plume are prime planetary objects in the Outer Solar System to perform in situ investigations. In the present paper, we describe the science goals and key measurements to be performed by a future exploration mission involving a Saturn-Titan orbiter and a Titan balloon, which was proposed to ESA in response to the call for definition of the science themes of the next Large-class mission in 2013. The mission scenario is built around three complementary science goals: (A) Titan as an Earth-like system; (B) Enceladus as an active cryovolcanic moon; and (C) Chemistry of Titan and Enceladus - clues for the origin of life. The proposed measurements would provide a step change in our understanding of planetary processes and evolution, with many orders of magnitude improvement in temporal, spatial, and chemical resolution over that which is possible with Cassini-Huygens. This mission concept builds upon the successes of Cassini-Huygens and takes advantage of previous mission heritage in both remote sensing and in situ measurement technologies.

future missions↗

Silicon Carbide Pressure Sensors for Venus Environment

We report on the evaluation of 4H-SiC piezoresistive pressure sensors in the simulated Venus environment of the NASA Glenn Extreme Environments Rig (GEER). The purpose of the evaluation was to determine the survivability of the pressure and temperature sensors and ancillary packaging components when subjected to the high pressure and aggressive chemical media that are characteristic of the Venus environment. Interest in Venus has been stimulated by the ongoing debate about Earth's planetary evolution, particularly in regards to its climate, and NASA has proposed a flagship mission to Venus to be launched in the near future. Quantifying how the Venus evo-lution ran its course will greatly aid researchers trying to model Earth's climate dynamics.

high temperature↗

Internal Electrostatic Discharge Testing of Inert Solid Rocket Motor Materials

Jupiter’s moon Europa is believed to have a global liquid-water ocean beneath its icy surface. As such, it is a highly interesting destination for explorers seeking signs of life outside of Earth. This interest has given rise to the Europa Lander Mission [Hand, et al., 2017]. The central goal of the Europa Lander Mission is to place a stationary lander on Europa and make surface and sub-surface measurements, dramatically improving understanding of this Jovian moon, and potentially detecting signs of life.Placing a lander on Europa will require multiple spacecraft elements deployed across a multi-year mission timeline. Some of the key elements include: a large payload capacity rocket, such as the Space Launch System (SLS), capable of providing direct Jupiter orbit insertion; a solar-powered carrier; a de-orbit system; a sky crane landing system; and, of course, the surface lander. A noteworthy fact is that the current design requires a large solid rocket motor to provide the necessary braking thrust for the de-orbit stage. While solid rocket motors have been used extensively by NASA during launch, in-space use has been limited. In addition to the normal challenges associated with a long-distance planetary mission, the Europa Lander Mission must also contend with the high-radiation environment associated with the Jovian system. The size of Jupiter, combined with its magnetic field strength, and rotation speed, result in a harsh radiation environment composed of high energy charged particles (ions and electrons) as well as high-temperature plasmas [de Soria-Santacruz Pich, 2016]. Due to this high-radiation environment, each component of the Europa Lander spacecraft must be evaluated to determine its radiation dose tolerance and its likelihood for experiencing electrostatic charging (and discharging). In general, metal components in a Jovian environment do not pose a concern for radiation degradation; in fact, metal structures and closeouts can act as radiation shielding for the more sensitive components. Charging of a metal component is only an issue if the component is not properly grounded to the spacecraft chassis. However, electrically insulating materials, such as polymers, are subject to radiation degradation as well as surface and internal charging, and therefore require extra scrutiny. The focus of this paper will be on the insulating materials that are commonly used inside solid rocket motors. The special application of a solid rocket motor used in space after a relatively long duration flight, combined with the high energy electron environment in the Jovian system, raises concerns about the possibility of significant charging and discharging leading to reduced performance.

Schneider, Todd A.↗

Radiation tests of highly scaled, high-density, commercial, nonvolatile NAND flash memories— update 2012

The space radiation environment poses a certain risk to all electronic components on Earth-orbiting and planetary mission spacecraft. In recent years, there has been increased interest in the use of high-density, commercial, nonvolatile flash memories in space because of ever-increasing data volumes and strict power requirements. They are used in a wide variety of spacecraft subsystems. At one end of the spectrum, flash memories are used to store small amounts of mission-critical data such as boot code or configuration files and, at the other end, they are used to construct multi-gigabyte data recorders that record mission science data. This report examines single-event effect (SEE) and total ionizing dose (TID) response in single-level cell (SLC) 32-Gb, multi-level cell (MLC) 64-Gb, and Triple-level (TLC) 64-Gb NAND flash memories manufactured by Micron Technology with feature size of 25 nm.

Allen, Gregory R.↗

Penetrator Science Objectives for the Moon and Artemis

Some key decadal-scale mission goals at the Moon have been proposed, these include sample return, the establishment of a lunar geophysical network, and exploring extreme environments, such as the permanently shadowed regions at the lunar poles. These environments present accessibility challenges, though contain significant rewards for science return. Small penetrator experiments have great potential for precursor and survey missions for the exploration of these environments, producing early science data and later mission planning. Penetrators have been conceptualized for planetary exploration for several decades but have yet to be operated successfully. Penetrators are designed to be self-contained vehicles with a suite of instruments de-signed to survive and function after achieving certain depth into the regolith using the kinetic energy of impact, or designed to measure mechanical (or compositional) properties as part of a much larger vehicle.

C. J. Ahrens↗

XHAB 2012 Final Report Habitat Demonstration Unit Lite

The University of Maryland Space Systems Laboratory (SSL) was awarded a NASA X-Hab 2012 grant for the design and construction of a new Earth analogue habitat for habitability research. This work builds on the past ECLIPSE and X-Hab projects at the SSL, by combining these elements with a new habitat module in order to create a single research platform for habitability studies. The “Crew Habitat Evaluator for Long-duration Orbital, Near-earth, and Interplanetary Applications” (CHELONIA) will deliver a much more flexible architecture than the previously developed mock-ups, allowing facilitating faster modification of the interior layouts and available total volume. This will enable the investigators to evaluate crew assessments and task performance as a function of the interior layout, functional area allocation and total available volume. This paper documents the design of this new infrastructure, and includes the details of the manufacturing of a new habitat mock-up module and modifications to the existing elements. The paper also includes a brief discussion of possible future research goals. Initial layouts are implemented using foam-core volumetric mock-ups for internal equipment and outfitting. These low fidelity mock-ups constitute a “library” that will allow a very rapid evaluation of a multitude of layouts. CHELONIA is also suitable for higher fidelity functional mock-ups, as well as short to medium-duration mission simulations. This new facility will enable the examination of habitat layouts for both partial gravity and microgravity environments. While partial gravity systems will be easily evaluated with the habitat currently in development, microgravity subsystems will be studied by utilizing low fidelity volumetric neutral buoyancy mock-ups in order to determine if commonality in the design for these two environments is appropriate. Finally, this new facility is being integrated into the SSL Moonyard planetary surface simulation center. The Moonyard simulates a planetary surface by means of a large sandbox, and is used primarily for rover field trials and suit systems evaluation. This new facility will be a prime element in future Earth analog simulations at the University of Maryland in support of NASA exploration objectives.

Kevin Davis↗

Development Efforts and Status of Plume-Surface Interaction Capabilities for Propulsive Landing Systems

Rocket plume-surface interaction is a multi-phase problem characterized by plume flow physics, erosion physics, and ejecta dynamics. All propulsive landers will experience plume-surface interaction. The risks posed by such effects can vary greatly as a function of the local environment, lander concept of operations, configuration, and physical scale. Prior Lunar and Martian landers have overcome challenges posed by these environments, on the basis of scaled ground testing and subsequent flight experience, but the landing systems for present and future missions are planning to operate increasingly outside of NASA's current experience with plume-surface interaction. This presentation discusses the current efforts and status of activities within NASA to progress understanding of fundamental plume-surface interaction physics, the capability to predict resulting environments and effects, and the definition of implications for current and future Lunar and planetary landing systems.

Landing↗

Optical Communication Subsystem for the X200 Series of Planetary Missions

NASA has started a major new Advanced Deep Space System Development (a.k.a x2000) Program at JPL. The objective of this program is to develop and space-qualify (in a total system environment) advanced, cutting-edge technologies for the next generation of deep-space exploration missions.

Optical Communication Planetary Missions Fire and ↗

The Electrostatic Environments of Mars and the Moon

The electrical activity present in the environment near the surfaces of Mars and the moon has very different origins and presents a challenge to manned and robotic planetary exploration missions. Mars is covered with a layer of dust that has been redistributed throughout the entire planet by global dust storms. Dust, levitated by these storms as well as by the frequent dust devils, is expected to be electrostatically charged due to the multiple grain collisions in the dust-laden atmosphere. Dust covering the surface of the moon is expected to be electrostatically charged due to the solar wind, cosmic rays, and the solar radiation itself through the photoelectric effect. Electrostatically charged dust has a large tendency to adhere to surfaces. NASA's Mars exploration rovers have shown that atmospheric dust falling on solar panels can decrease their efficiency to the point of rendering the rover unusable. And as the Apollo missions to the moon showed, lunar dust adhesion can hinder manned and unmanned lunar exploration activities. Taking advantage of the electrical activity on both planetary system bodies, dust removal technologies are now being developed that use electrostatic and dielectrophoretic forces to produce controlled dust motion. This paper presents a short review of the theoretical and semiempirical models that have been developed for the lunar and Martian electrical environments.

Calle, Carlos I.↗

An ethnographic object-oriented analysis of explorer presence in a volcanic terrain environment: Claims and evidence

An ethnographic field study was conducted to investigate the nature of presence in field geology, and to develop specifications for domain-based planetary exploration systems utilizing virtual presence. Two planetary geologists were accompanied on a multi-day geologic field trip that they had arranged for their own scientific purposes, which centered on an investigation of the extraordinary xenolith/nodule deposits in the Kaupulehu lava flow of Hualalai Volcano, on the island of Hawaii. The geologists were observed during the course of their field investigations and interviewed regarding their activities and ideas. Analysis of the interview resulted in the identification of key domain entities and their attributes, relations among the entities, and explorer interactions with the environment. The results support and extend the author's previously reported continuity theory of presence, indicating that presence in field geology is characterized by persistent engagement with objects associated by metonymic relations. The results also provide design specifications for virtual planetary exploration systems, including an integrating structure for disparate data integration. Finally, the results suggest that unobtrusive participant observation coupled with field interviews is an effective research methodology for engineering ethnography.

Mcgreevy, Michael W.↗

Rover mounted ground penetrating radar as a tool for investigating the near-surface of Mars and beyong

In spite of the highly successful nature of recent planetary missions to the terrestrial planets and outer satellites a number of questions concerning the evolution of their surfaces remain unresolved. For example, knowledge of many characteristics of the stratigraphy and soils comprising the near-surface on Mars remains largely unknown, but is crucial in order to accurately define the history of surface processes and near-surface sedimentary record. Similar statements can be made regarding our understanding of near-surface stratigraphy and processes on other extraterrestrial planetary bodies. Ground penetrating radar (GPR) is a proven and standard instrument capable of imaging the subsurface at high resolution to 10's of meters depth in a variety of terrestrial environments. Moreover, GPR is portable and easily modified for rover deployment. Data collected with a rover mounted GPR could resolve a number of issues related to planetary surface evolution by defining shallow stratigraphic records and would provide context for interpreting results of other surface analyses (e.g. elemental or mineralogical). A discussion of existing GPR capabilities is followed first by examples of how GPR might be used to better define surface evolution on Mars and then by a brief description of possible GPR applications to the Moon and other planetary surfaces.

Grant, J. A.↗

N2 Chemistry in Interstellar and Planetary Ices: Radiation-Driven Oxidation

As part of our work on nitrogen-rich ices, the IR spectra and band strengths used in a recent paper to identify and quantify radiation-induced changes in an N2+H2O ice near 15 K are examined, along with reports of (i) a chemical tracer for N2+H2O ices, (ii) a new IR feature of solid N2, and (iii) a striking 15N isotopic enrichment. Problems are found for each IR band strength used and for each of the three claims made, to the extent that none are supported by the results presented to date. In contrast, new work presented here, combined with several older investigations, strongly supports the formation of di- and triatomic nitrogen oxides in irradiated N2-rich ices. Observations and trends in the chemistry of N2-rich icy solids are described, and conclusions are drawn. A considerable amount of material from previous chemical studies of N2-rich systems, spanning more than a century, is brought together for the rst time and used to examine the chemistry of N2-rich ices in extraterrestrial environments. Needs are identied and suggestions made for future studies of N2-rich interstellar and planetary ice analogs.

astrobiology↗

N2 Chemistry in Interstellar and Planetary Ices: Radiation-Driven Oxidation

As part of our work on nitrogen-rich ices, the IR spectra and band strengths used in a recent paper to identify and quantify radiation-induced changes in an N2+H2O ice near 15 K are examined, along with reports of (i) a chemical tracer for N2+H2O ices, (ii) a new IR feature of solid N2, and (iii) a striking 15N isotopic enrichment. Problems are found for each IR band strength used and for each of the three claims made, to the extent that none are supported by the results presented to date. In contrast, new work presented here, combined with several older investigations, strongly supports the formation of di- and triatomic nitrogen oxides in irradiated N2-rich ices. Observations and trends in the chemistry of N2-rich icy solids are described, and conclusions are drawn. A considerable amount of material from previous chemical studies of N2-rich systems, spanning more than a century, is brought together for the first time and used to examine the chemistry of N2-rich ices in extraterrestrial environments. Needs are identified and suggestions made for future studies of N2-rich interstellar and planetary ice analogs

astrobiology – astrochemistry – infrared: ISM – IS↗