Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “explorer”

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 883 records · Page 49
All sourcesNASA NTRSDOE OSTI
NASA NTRS1992

Medicine on Mars: Remote medical care and the space exploration initiative

Mars exploration missions as described in the Synthesis Group report will involve extended exposures of crew members to remote, hazardous environments for up to 100 days. Maintenance of crew health and performance will be critical to ensure mission success. Because of the great distances between the Earth and Mars, round trip telecommunication will take from seven to forty minutes and immediate return to Earth will not be feasible: an autonomous medical care system that integrates preventive, occupational, and environmental aspects of health care and provides diagnostic and treatment capabilities will be necessary. Providing medical care for Mars explorers will pose some unique technical and engineering challenges. Medical care equipment will need to be designed to be modular and portable to ensure that it is interchangeable between vehicle and planetary surface elements. Miniaturization will be necessary to reduce mass and volume. Computerized systems that automatically acquire and manage medical information and provide medical references (literature), decision support, and automated medical record keeping will be a crucial part of a Martian medical care system. Medical care will also rely on remote consultation with Earth-based specialists. This presentation will provide an overview of the health and medical concerns associated with Mars exploration missions and will describe some specific concepts for Mars medical care systems.

Simmons, S. C.↗
NASA NTRS1994

Terrain modelling and motion planning for an autonomous exploration rover

To assess the feasibility of planetary exploration missions using rovers, the French national agency CNES, with a consortium of European laboratories and industrial concerns, has initiated the Eureka project, 'Illustration of an Autonomous Robot for the Exploration of Space' (IARES). IARES is a demonstrator composed of a rover and a ground station, linked by telemetry and telecommand. It is aimed at verifying, on earth, robotic concepts developed by the RISP group of French laboratories (LAAS, INRIA, CERT, LETI) to perform scientific missions such as autonomous terrain sample collecting over large areas. To cope with the actual needs of planet exploration, IARES suitability is assessed through constraints on limited bandwidth, time delay and on-board resources. This autonomy relies heavily on robust onboard trajectory generation capabilities. This paper presents the main functions of the IARES navigation sub-system and shows how they are combined to allow movement in Mars-like environments. Section 2 gives an overall description of the IARES system. Section 3 details the functions of the Navigation sub-system, and finally, section 4 illustrates with a simple example the use of these functions.

Richard, F.↗
NASA NTRS1990

[Space Exploration Initiative]

Future Mars exploration missions and operations are discussed using computer animation along with proposed vehicles and equipment, for example, a Mars surface land rover. There is a Presidential Address by President George Bush where he discusses future goals for space exploration. This video also outlines the Outreach Program, which offers the public the chance to suggest new ideas for space research and exploration.

Source record↗
NASA NTRS1994

Future NASA plans for exobiology and solar system exploration

The prominence of exobiology as a part of the NASA program in solar system exploration reached its peak during the Viking missions of the mid-1970's. Even before those missions were finished, the Exobiology Program had been transferred out of the Division responsible for solar system exploration, and many of the direct ties to future missions became more difficult to make, providing a bureaucratic impediment to the conduct of exobiology research in space. Early in 1993, the Exobiology Program was brought back in to the Solar System Exploration Division, as an integral part of NASA's program to study this and other solar systems. As such, the Program stands to gain from an overall broad investment in missions that will study Mars, small bodies such as asteroids and comets, and outer planetary bodies such as Saturn, Titan, and even Pluto. Additional opportunities may be forthcoming on the Moon and elsewhere in Earth-orbit. Ground-based studies will continue to be an important foundation for work in space, while additional effects will be continue to use ground-based astronomical instruments to study other planetary systems, and to search for life on planets around other stars. This paper provides a current planning and budgetary prospectus on the future of Exobiology in NASA.

Rummel, John D.↗
NASA NTRS1995

Exobiological exploration of Mars

Of all the other planets in the solar system, Mars remains the most promising for further elucidating concepts about chemical evolution and the origin of life. Strategies were developed to pursue three exobiological objectives for Mars exploration: determining the abundance and distribution of the biogenic elements and organic compounds, detecting evidence of an ancient biota on Mars, and determining whether indigenous organisms exist anywhere on the planet. The three strategies are quite similar and, in fact, share the same sequence of phases. In the first phase, each requires global reconnaissance and remote sensing by orbiters to select sites of interest for detailed in situ analyses. In the second phase, lander missions are conducted to characterize the chemical and physical properties of the selected sites. The third phase involves conducting 'critical' experiments at sites whose properties make them particularly attractive for exobiology. These critical experiments would include, for example, identification of organics, detection of fossils, and detection of extant life. The fourth phase is the detailed analysis of samples returned from these sites in Earth-based laboratories to confirm and extend previous discoveries. Finally, in the fifth phase, human exploration is needed to establish the geological settings for the earlier findings or to discover and explore sites that are not accessible to robotic spacecraft.

Klein, H. P.↗
NASA NTRS1995

The transition region and coronal explorer (TRACE)

The transition region and coronal explorer (TRACE) NASA small explorer mission and instrument are presented. The TRACE scientific investigation explores the relationships between fine-scale magnetic fields and the associated solar plasma structures. The instrument collects images of solar plasmas at temperatures from 10(exp 4) to 10(exp 7) K with one arcsec spatial resolution. The design specifications of the trace instrument are presented.

Title, Alan↗
NASA NTRS1996

Exploring Mars for Evidence of Past or Present Life: Roles of Robotic and Human Missions

During the coming decade, robotic field science will play a fundamental role in exploring Mars for evidence of past life and/or prebiotic chemistry. To create a context for such exploration, we especially need to understand the mineralogy and chemistry of the Martian surface. We have learned that the preservation of biological signatures in rocks on Earth is favored by rapid mineralization processes that are restricted to a comparatively small number of geological settings. Thus, a detailed knowledge of surface mineralogy will provide valuable clues about past Martian environments as a necessary context for future exobiological exploration.

Farmer, Jack D.↗
NASA NTRS1997

The Polar Exploration of Mars

Apart from the Earth, Mars is the only planet in our Solar System to possess significant and traversable polar caps that could potentially play host to a long term program of human polar exploration. Such explorations may provide valuable information on the structure of the martian poles, both geologically and from the point of view of gaining an increased insight into volatile cycling in the martian atmosphere, past and present. Here some initial considerations are made on the nature and methods for the human exploration of the martian poles and the scientific objectives that might be prioritized for such missions. The first proposed strategies and routes for overland Mars polar expeditions, using the nature of terrestrial polar expedition attempts as a template, are also suggested.

Cockell, C. S.↗
NASA NTRS1997

Shielding Strategies for Human Space Exploration

A group of twenty-nine scientists and engineers convened a 'Workshop on Shielding Strategies for Human Space Exploration' at the Lyndon B. Johnson Space Center in Houston, Texas. The provision of shielding for a Mars mission or a Lunar base from the hazards of space radiations is a critical technology since astronaut radiation safety depends on it and shielding safety factors to control risk uncertainty appear to be great. The purpose of the workshop was to define requirements for the development and evaluation of high performance shield materials and designs and to develop ideas regarding approaches to radiation shielding. The workshop was organized to review the recent experience on shielding strategies gained in studies of the 'Space Exploration Initiative (SEI),' to review the current knowledge base for making shield assessment, to examine a basis for new shielding strategies, and to recommend a strategy for developing the required technologies for a return to the moon or for Mars exploration. The uniqueness of the current workshop arises from the expected long duration of the missions without the protective cover of the geomagnetic field in which the usually small and even neglected effects of the galactic cosmic rays (GCR) can no longer be ignored. It is the peculiarity of these radiations for which the inter-action physics and biological action are yet to be fully understood.

Wilson J. W.↗
NASA NTRS1998

Mars Human Exploration Reference Mission

This presentation proposes the next steps for human exploration of Mars. The presentation reviews the reasons for human exploration of Mars. Two different trajectories are proposed: (1) for a long stay mission, and (2) for a short term mission, which could also include a swing by Venus. A reference mission scenario is investigated, which includes forward deployment of two cargo missions, followed by a human piloted mission. The power needs of such a mission include nuclear thermal propulsion, and the possible use of Mars in situ resources. The exploration will require electric propulsion, stationary power source, and a mobile power source. The trajectories required for electric propulsion of earth are shown, and the engineering of a Mars Transportation Habitat are reviewed.

Drake, Bret↗
NASA NTRS1998

Preparing for Human Exploration

NASA's Human Exploration and Development of Space (HEDS) Enterprise is defining architectures and requirements for human exploration that radically reduce the costs of such missions through the use of advanced technologies, commercial partnerships and innovative systems strategies. In addition, the HEDS Enterprise is collaborating with the Space Science Enterprise to acquire needed early knowledge about Mars and to demonstrate critical technologies via robotic missions. This paper provides an overview of the technological challenges facing NASA as it prepares for human exploration. Emphasis is placed on identifying the key technologies including those which will provide the most return in terms of reducing total mission cost and/or reducing potential risk to the mission crew. Top-level requirements are provided for those critical enabling technology options currently under consideration.

Drake, Bret G.↗
NASA NTRS1998

Exploration of the Moon with Remote Sensing, Ground-Penetrating Radar, and the Regolith-Evolved Gas Analyzer (REGA)

There are two important reasons to explore the Moon. First, we would like to know more about the Moon itself: its history, its geology, its chemistry, and its diversity. Second, we would like to apply this knowledge to a useful purpose. namely finding and using lunar resources. As a result of the recent Clementine and Lunar Prospector missions, we now have global data on the regional surface mineralogy of the Moon, and we have good reason to believe that water exists in the lunar polar regions. However, there is still very little information about the subsurface. If we wish to go to the lunar polar regions to extract water, or if we wish to go anywhere else on the Moon and extract (or learn) anything at all, we need information in three dimensions an understanding of what lies below the surface, both shallow and deep. The terrestrial mining industry provides an example of the logical steps that lead to an understanding of where resources are located and their economic significance. Surface maps are examined to determine likely locations for detailed study. Geochemical soil sample surveys, using broad or narrow grid patterns, are then used to gather additional data. Next, a detailed surface map is developed for a selected area, along with an interpretation of the subsurface structure that would give rise to the observed features. After that, further sampling and geophysical exploration are used to validate and refine the original interpretation, as well as to make further exploration/ mining decisions. Integrating remotely sensed, geophysical, and sample datasets gives the maximum likelihood of a correct interpretation of the subsurface geology and surface morphology. Apollo-era geophysical and automated sampling experiments sought to look beyond the upper few microns of the lunar surface. These experiments, including ground-penetrating radar and spectrometry, proved the usefulness of these methods for determining the best sites for lunar bases and lunar mining operations.

Cooper, B. L.↗
NASA NTRS1998

Exploring Aristarchus Plateau as a Potential Lunar Base Site

As part the exploration strategy, NASA has been studying the feasibility of a low cost human return to the Moon. The currently planned mission has a dual focus on the advancement of lunar science and the use of in situ resources. Thus far, our space exploration plans have relied almost exclusively on equipment and supplies transported from Earth. This may be appropriate for operations in Earth orbit, or for short duration stays on the lunar surface. However, the ability to "live off the land," will prove vital for long term habitation of the Moon and planets. This study takes a close look at the Aristarchus Plateau, one of the primary candidate sites for human lunar exploration. Based on this synthesis study, we recommend two sites on the Aristarchus Plateau that will maximize science return and provide a convincing demonstration of the use of in situ resources and which may be a viable future lunar base site.

Coombs, Cassandra R.↗
NASA NTRS1999

Dust on Mars: An Aeolian Threat to Human Exploration?

The NASA HEDS Program is duly concerned for human explorers regarding the potential hazard posed by the ubiquitous dust mantle on Mars. To evaluate properties of dust that could be hazardous to humans, the MPS 2001 Lander payload will include the Mars Environmental Compatibility Assessment (MECA) experiment. This includes optical and atomic-force microscopy to evaluate soil grains for shape and size, wet chemistry to evaluate toxic substances, electrometry to evaluate triboelectric charging, and test-material palets to evaluate electrostatic and magnetic adhesion, and the hardness/abrasiveness of soil grains; these experimental subcomponents are delivered samples by the camera-equipped robotic arm of the lander which will acquire material from depths of 0.5 to 1.0 m in the soil. Data returned by MECA will be of value to both the BEDS and planetary/astrobiology communities. Dust poses a threat to human exploration because the martian system does not hydrologically or chemically remove fine particles that are being continuously generated by thermal, aeolian, and colluvial weathering, and by volcanism and impact over billions of years. The dust is extremely fine-grained, in copious quantities, ubiquitous in distribution, continually mobile, and a source of poorly-grounded static charges -- a suite of characteristics posing a particulate and electrical threat to explorers and their equipment. Dust is mobilized on global and regional scales, but probably also unpredictably and violently at local scales by dust devils. The latter might be expected in great abundance owing to near surface atmospheric instability (dust devils were detected by Pathfinder during its brief lifetime). Preliminary laboratory experiments suggest that space-suit materials subjected to windblown dust may acquire a uniform, highly adhesive dust layer that is also highly cohesive laterally owing to electrostatic forces. This layer will obscure visibility through the helmet visor, penetrate joints and fabrics, change the thermal properties of the suit, and possibly affect electronic/electrical suit functions. It is paramount that future missions address the issue of interparticle forces, and in particular, the role played by ionizing radiation in affecting these forces on Mars.

Marshall, J.↗
NASA NTRS1999

Dust on Mars: An Aeolian Threat to Human Exploration?

The NASA HEDS Program is duly concerned for human explorers regarding the potential hazard posed by the ubiquitous dust mantle on Mars. To evaluate properties of dust that could be hazardous to humans, the NMS 2001 Lander payload will include the Mars Environmental Compatibility Assessment (MECA) experiment. This includes optical and atomic-force microscopy to evaluate soil grains for shape and size, wet chemistry to evaluate toxic substances, electrometry to evaluate triboelectric charging, and test-material palets to evaluate electrostatic and magnetic adhesion, and the hardness/abrasiveness of soil grains; these experimental subcomponents are delivered samples by the camera-equipped robotic arm of the lander which will acquire material from depths of 0.5 to 1.0 m in the soil. Data returned by MECA will be of value to both the hEDS and planetary/astrobiology communities. Dust poses a threat to human exploration because the martian system does not hydrologically or chemically remove fine particles that are being continuously generated by thermal, aeolian, and colluvial weathering, and by volcanism and impact over billions of years. The dust is extremely fine-grained, in copious quantities, ubiquitous in distribution, continually mobile, and a source of poorly-grounded static charges -- a suite of characteristics posing a particulate and electrical threat to explorers and their equipment. Dust is mobilized on global and regional scales, but probably also unpredictably and violently at local scales by dust devils. The latter might be expected in great abundance owing to near surface atmospheric instability (dust devils were detected by Pathfinder during its brief lifetime). Preliminary laboratory experiments suggest that space-suit materials subjected to windblown dust may acquire a uniform, highly adhesive dust layer that is also highly cohesive laterally owing to electrostatic forces. This layer will obscure visibility through the helmet visor, penetrate joints and fabrics, change the thermal properties of the suit, and possibly affect electronic/electrical suit functions. It is paramount that future missions address the issue of interparticle forces, and in particular, the role played by ionizing radiation in affecting these forces on Mars.

Marshall, J.↗
NASA NTRS1998

Mission to the Solar System: Exploration and Discovery. A Mission and Technology Roadmap

Solar System exploration addresses some of humanity's most fundamental questions: How and when did life form on Earth? Does life exist elsewhere in the Solar System or in the Universe? - How did the Solar System form and evolve in time? - What can the other planets teach us about the Earth? This document describes a Mission and Technology Roadmap for addressing these and other fundamental Solar System Questions. A Roadmap Development Team of scientists, engineers, educators, and technologists worked to define the next evolutionary steps in in situ exploration, sample return, and completion of the overall Solar System survey. Guidelines were to "develop aa visionary, but affordable, mission and technology development Roadmap for the exploration of the Solar System in the 2000 to 2012 timeframe." The Roadmap provides a catalog of potential flight missions. (Supporting research and technology, ground-based observations, and laboratory research, which are no less important than flight missions, are not included in this Roadmap.)

Gulkis, S.↗
NASA NTRS2000

In Space Nuclear Power as an Enabling Technology for Deep Space Exploration

Deep Space Exploration missions, both for scientific and Human Exploration and Development (HEDS), appear to be as weight limited today as they would have been 35 years ago. Right behind the weight constraints is the nearly equally important mission limitation of cost. Launch vehicles, upper stages and in-space propulsion systems also cost about the same today with the same efficiency as they have had for many years (excluding impact of inflation). Both these dual mission constraints combine to force either very expensive, mega systems missions or very light weight, but high risk/low margin planetary spacecraft designs, such as the recent unsuccessful attempts for an extremely low cost mission to Mars during the 1998-99 opportunity (i.e., Mars Climate Orbiter and the Mars Polar Lander). When one considers spacecraft missions to the outer heliopause or even the outer planets, the enormous weight and cost constraints will impose even more daunting concerns for mission cost, risk and the ability to establish adequate mission margins for success. This paper will discuss the benefits of using a safe in-space nuclear reactor as the basis for providing both sufficient electric power and high performance space propulsion that will greatly reduce mission risk and significantly increase weight (IMLEO) and cost margins. Weight and cost margins are increased by enabling much higher payload fractions and redundant design features for a given launch vehicle (higher payload fraction of IMLEO). The paper will also discuss and summarize the recent advances in nuclear reactor technology and safety of modern reactor designs and operating practice and experience, as well as advances in reactor coupled power generation and high performance nuclear thermal and electric propulsion technologies. It will be shown that these nuclear power and propulsion technologies are major enabling capabilities for higher reliability, higher margin and lower cost deep space missions design to reliably reach the outer planets for scientific exploration.

Sackheim, Robert L.↗
NASA NTRS1999

Exploration of Uncertainty in Glacier Modelling

There are procedures and methods for verification of coding algebra and for validations of models and calculations that are in use in the aerospace computational fluid dynamics (CFD) community. These methods would be efficacious if used by the glacier dynamics modelling community. This paper is a presentation of some of those methods, and how they might be applied to uncertainty management supporting code verification and model validation for glacier dynamics. The similarities and differences between their use in CFD analysis and the proposed application of these methods to glacier modelling are discussed. After establishing sources of uncertainty and methods for code verification, the paper looks at a representative sampling of verification and validation efforts that are underway in the glacier modelling community, and establishes a context for these within overall solution quality assessment. Finally, an information architecture and interactive interface is introduced and advocated. This Integrated Cryospheric Exploration (ICE) Environment is proposed for exploring and managing sources of uncertainty in glacier modelling codes and methods, and for supporting scientific numerical exploration and verification. The details and functionality of this Environment are described based on modifications of a system already developed for CFD modelling and analysis.

Thompson, David E.↗