Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “planetary bodies”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
NASA NTRS2012

Moon Search Algorithms for NASA's Dawn Mission to Asteroid Vesta

A moon or natural satellite is a celestial body that orbits a planetary body such as a planet, dwarf planet, or an asteroid. Scientists seek understanding the origin and evolution of our solar system by studying moons of these bodies. Additionally, searches for satellites of planetary bodies can be important to protect the safety of a spacecraft as it approaches or orbits a planetary body. If a satellite of a celestial body is found, the mass of that body can also be calculated once its orbit is determined. Ensuring the Dawn spacecraft's safety on its mission to the asteroid Vesta primarily motivated the work of Dawn's Satellite Working Group (SWG) in summer of 2011. Dawn mission scientists and engineers utilized various computational tools and techniques for Vesta's satellite search. The objectives of this paper are to 1) introduce the natural satellite search problem, 2) present the computational challenges, approaches, and tools used when addressing this problem, and 3) describe applications of various image processing and computational algorithms for performing satellite searches to the electronic imaging and computer science community. Furthermore, we hope that this communication would enable Dawn mission scientists to improve their satellite search algorithms and tools and be better prepared for performing the same investigation in 2015, when the spacecraft is scheduled to approach and orbit the dwarf planet Ceres.

planetary sciences↗
NASA NTRS1977

Thermal evolution of planetary size bodies

The size dependence of planetary thermal evolution is investigated through calculations which take into account the effects of heat source differentiation and convection. The theoretical computations make use of hypothetical bodies for minor planets; Mercury, Venus and Mars are employed to represent the size spectrum of the inner planets. If started at a cold initial condition, an object with a radius less than 1000 km is unlikely to reach melting. Accretional heating, inductive heating and short half-life radioactive heating are among the mechanisms which may produce early melting and differentiation in larger planets. Core formation in Mercury and Venus is also discussed.

Hsui, A. T.↗
NASA NTRS1973

Characteristics of Coupled Nongray Radiating Gas Flows with Ablation Product Effects About Blunt Bodies During Planetary Entries

A computational method was developed for the fully-coupled solution of nongray, radiating gas flows with ablation product effects about blunt bodies during planetary entries. The treatment of radiation accounts for molecular band, continuum, and atomic line transitions with a detailed frequency dependence of the absorption coefficient. The ablation of the entry body was solved as part of the solution for a steady-state ablation process. The method was applied by results at typical conditions during entry to Venus. The radiative heating rates along the downstream region of the body can exceed the stagnation point value. The radiative heating to the body is attenuated in the boundary layer at the downstream region of the body and at the stagnation point of the body. A study of the radiation, inviscid flow about spherically capped, conical bodies during planetary entries shows that the nondimensional, radiative heating distributions are nonsimilar with entry conditions. Caution should be exercised in attempting to extrapolate results from known distributions to other entry conditions for which solutions have not yet been obtained.

Sutton, K.↗
NASA NTRS2009

Blue Marble Matches: Using Earth for Planetary Comparisons

Goal: This activity is designed to introduce students to geologic processes on Earth and model how scientists use Earth to gain a better understanding of other planetary bodies in the solar system. Objectives: Students will: 1. Identify common descriptor characteristics used by scientists to describe geologic features in images. 2. Identify geologic features and how they form on Earth. 3. Create a list of defining/distinguishing characteristics of geologic features 4. Identify geologic features in images of other planetary bodies. 5. List observations and interpretations about planetary body comparisons. 6. Create summary statements about planetary body comparisons.

Graff, Paige Valderrama↗
NASA NTRS2022

Tidal Insights into Rocky and Icy Bodies: An Introduction and Overview

Solid body tides provide key information on the interior structure, evolution, and origin of the planetary bodies. Our Solar system harbours a very diverse population of planetary bodies, including those composed of rock, ice, gas, or a mixture of all. While a rich arsenal of geophysical methods has been developed over several years to infer knowledge about the interior of the Earth, the inventory of tools to investigate the interiors of other Solar-system bodies remains limited. With seismic data only available for the Earth, the Moon, and Mars, geodetic measurements, including the observation of the tidal response, have become especially valuable and therefore, has played an important role in understanding the interior and history of several Solar system bodies. To use tidal response measurements as a means to obtain constraints on the interior structure of planetary bodies, appropriate understanding of the viscoelastic reaction of the materials from which the planets are formed is needed. Here, we review the fundamental aspects of the tidal modeling and the information on the present-day interior properties and evolution of several planets and moons based on studying their tidal response. We begin with an outline of the theory of viscoelasticity and tidal response. Next, we proceed by discussing the information on the tidal response and the inferred structure of Mercury, Venus, Mars and its moons, the Moon, and the largest satellites of giant planets, obtained from the analysis of the data that has been provided by space missions. We also summarise the upcoming possibilities offered by the currently planned missions.

Tides↗
NASA NTRS1964

Theory of Tumbling Bodies Entering Planetary Atmospheres with Application to Probe Vehicles and the Australian Tektites

The tumbling motion of aerodynamically stable bodies entering planetary atmospheres is analyzed considering that the tumbling, its arrest, and the subsequent oscillatory motion are governed by the equation for the fifth Painleve' transcendent. Results based on the asymptotic behavior of the transcendent are applied to study (1) the oscillatory behavior of planetary probe vehicles in relation to aerodynamic heating and loads and (2) the dynamic behavior of the Australian tektites on entering the Earth's atmosphere, under the hypothesis that their origin was the Moon.

Tobak, Murray↗
NASA NTRS2017

Meteorite Dust and Health - A Novel Approach for Determining Bulk Compositions for Toxicological Assessments of Precious Materials

With the resurgence of human curiosity to explore planetary bodies beyond our own, comes the possibility of health risks associated with the materials covering the surface of these planetary bodies. In order to mitigate these health risks and prepare ourselves for the eventuality of sending humans to other planetary bodies, toxicological evaluations of extraterrestrial materials is imperative (Harrington et al. 2017). Given our close proximity, as well as our increased datasets from various missions (e.g., Apollo, Mars Exploration Rovers, Dawn, etc…), the three most likely candidates for initial human surface exploration are the Moon, Mars, and asteroid 4Vesta. Seven samples, including lunar mare basalt NWA 4734, lunar regolith breccia NWA 7611, martian basalt Tissint, martian regolith breccia NWA 7034, a vestian basalt Berthoud, a vestian regolith breccia NWA 2060, and a terrestrial mid-ocean ridge basalt, were examined for bulk chemistry, mineralogy, geochemical reactivity, and inflammatory potential. In this study, we have taken alliquots from these samples, both the fresh samples and those that underwent iron leaching (Tissint, NWA 7034, NWA 4734, MORB), and performed low pressure, high temperature melting experiments to determine the bulk composition of the materials that were previously examined.

Vander Kaaden, K. E.↗
NASA NTRS2005

Processing of Lunar Soil Simulant for Space Exploration Applications

NASA's long-term vision for space exploration includes developing human habitats and conducting scientific investigations on planetary bodies, especially on Moon and Mars. Processing and utilization of planetary in-situ resources is recognized as an important element of this vision since it can minimize the level of up-mass that will have to be transported from earth to the planetary bodies. Within this scope and context, we have undertaken a general effort aimed primarily at extracting and refining metals, developing glass, glass-ceramic, or traditional ceramic type materials using lunar soil simulants. In this paper we will present preliminary results on our effort on simultaneous carbothermal reduction of oxides for elemental extraction and zone refining for obtaining high purity metals. In additions we will demonstrate the possibility of developing glass fibers as reinforcement agents for planetary habitat construction, glasses for fixing nuclear waste from potential nuclear power generators, and glasses for magnetic applications. The paper will also include initial thermal characterization of the glasses produced from lunar simulant. Compositional analysis of processed samples will be presented.

Sen, Subhayu↗
NASA NTRS1962

Study of a Proposed Infrared Horizon Scanner for Use in Space-Orientation Control Systems

An attitude-sensing device for space vehicles which detects the thermal radiation discontinuity at opposite horizons of a planetary body to produce an attitude error signal is described. The planetary body may be the Earth, its Moon, Mars, or Venus. The sensor is expected to have an accuracy of 0.25 degrees for the Earth, a long continuous operating lifetime, a wide altitude range, a wide capture capability, and an inherent ability to produce signals indicating vehicle altitude. An experimental model incorporating many of the features of the proposed sensor indicates that the proposed sensor will be low in weight, volume, and power consumption. The sensor's altitude range, accuracy, lifetime, and sensitivity to radiation from the Moon and planets are discussed.

INFRARED HORIZON SCANNER↗
NASA NTRS1979

Tectonics and volcanisms of Mars

Televised images of Mars transmitted from interplanetary stations are used to develop a theory of the structure and development of the planet. Crater chronology, the structure of planetary bodies in the Earth group, and a comparison of the Earth planetary bodies are among the factors included.

Kats, Y. G.↗
NASA NTRS1994

Remote geochemical experiment package for Discovery class missions

Remote sensing x-ray and gamma-ray spectrometers can be used to infer elemental composition on atmosphereless bodies, such as asteroids, the moon, and Mercury. The composition of the planetary body and variations in its surface chemistry are of fundamental importance in understanding the formation and dynamics of that body. Thus, for Discovery class missions, x-ray fluorescence (XRF), gamma-ray spectrometer (GRS), or a combined Geochemical Experiment Package (GEP) have been proposed. These instruments can meet the mission science objectives, while still meeting the weight, power, and cost constraints. These missions include the Near Earth Asteroid Rendezvous, the Main-belt Asteroid Rendezvous, and others such as HERMES (Mercury Orbiter). This paper presents the results of calculations done to assess the sensitivity of a combined instrument to obtain elemental compositions of planetary bodies with an uncertainty small enough to be scientifically useful.

Clark, Pamela E.↗