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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 1,621 records · Page 90
All sourcesNASA NTRSDOE OSTI
NASA NTRS1991

The Space Exploration Initiative - An information system perspective

The authors look at the Space Exploration Initiative (SEI) from an information system perspective an discuss information system definition effort being conducted in support of NASAs Lunar Mars Exploration Program Office (LMEPO) Johnson Space Center (JSC). The development of an integrated, effective SEI information system (SIS) is recognized as crucial to the success of the SEI missions. Some of the new and unique challenges for the SIS as evidenced in the Lunar and the Mars missions are outlined along with some preliminary conceptual approaches, both architectural and technological, being investigated to address them.

Hartenstein, Ray↗
NASA NTRS1992

Doing more with less - The new way of exploring the solar system

Exploration of the solar system is considered in the light of existing economic factors and scientific priorities, and a general blueprint for an exploration strategy is set forth. Attention is given to mission costs, typical schedules, and the scientific findings of typical projects which create the need for collaboration and diversification in mission development. The combined technologies and cooperative efforts of several small organizations can lead to missions with short schedules and low costs.

Ridenoure, Rex↗
NASA NTRS1991

Telepresence for planetary exploration

Telepresence from a manned central base to unmanned rovers is discussed as a possible solution to the problem of human presence in planetary field geology. Some issues that are essential to planetary surface field work are examined with reference to results of the Amboy field study. The discussion emphasizes the exploration behavior and user-based requirements for effective telepresence systems for planetary exploration.

Mcgreevy, Michael W.↗
NASA NTRS1992

Attitude control system conceptual design for the X-ray timing explorer

The X-ray Timing Explorer (XTE) satellite is the next in a long series of Explorer-class missions developed by NASA. It will study the structure and dynamics of compact X-ray sources, neutron stars, white dwarfs, and other stellar objects with X-ray energy emissions. The demanding pointing requirement of XTE are driving the attitude control system design. This design is further complicated by large moving instruments which impart significant momentum on the spacecraft. The attitude control system concept to meet the XTE science objectives is discussed.

Bauer, Frank H.↗
NASA NTRS1992

Needs for supervised space robots in space exploration

The areas of application for space robots in the Space Exploration Initiative (SEI) are examined by reviewing the roles of SEI supervised robots particularly with planet-surface systems (PSSs). Treatment is given to both teleoperated conventional robot systems and autonomous intelligent systems for comparison in terms of safety, reliability, and productivity. Two development stages are proposed including one with a robotic actor, human observer, and a human supervisor and a second in which a closed-loop control and monitoring system is established. The use of remote control is shown to require robustness, self-calibration and -diagnosis, adjustable autonomy, and multitask capability. The requirements of intelligent control are also listed so that the PSSs of the SEI can be used to enable surface exploration, local-resource utilization potential, and reductions of human tasks.

Erickson, Jon D.↗
NASA NTRS1992

Nuclear thermal propulsion transportation systems for lunar/Mars exploration

Nuclear thermal propulsion technology development is underway at NASA and DoE for Space Exploration Initiative (SEI) missions to Mars, with initial near-earth flights to validate flight readiness. Several reactor concepts are being considered for these missions, and important selection criteria will be evaluated before final selection of a system. These criteria include: safety and reliability, technical risk, cost, and performance, in that order. Of the concepts evaluated to date, the Nuclear Engine for Rocket Vehicle Applications (NERVA) derivative (NDR) is the only concept that has demonstrated full power, life, and performance in actual reactor tests. Other concepts will require significant design work and must demonstrate proof-of-concept. Technical risk, and hence, development cost should therefore be lowest for the concept, and the NDR concept is currently being considered for the initial SEI missions. As lighter weight, higher performance systems are developed and validated, including appropriate safety and astronaut-rating requirements, they will be considered to support future SEI application. A space transportation system using a modular nuclear thermal rocket (NTR) system for lunar and Mars missions is expected to result in significant life cycle cost savings. Finally, several key issues remain for NTR's, including public acceptance and operational issues. Nonetheless, NTR's are believed to be the 'next generation' of space propulsion systems - the key to space exploration.

Clark, John S.↗
NASA NTRS1991

Solar System Exploration Division Strategic Plan, volume 1. Executive summary and overview

This first document is the first of a six-volume series presenting the Solar System Exploration Division's Strategic Plan for the 10-year period FY 1994 to FY 2003. The overall strategy is characterized by five fundamental precepts: (1) execute the current program; (2) improve the vitality of the program and the planetary science community; (3) initiate innovative, small, low-cost planetary missions; (4) initiate new major and moderate missions; and (5) prepare for the next generation of missions. This Strategic Plan describes in detail our proposed approach to accomplish these goals. Volume 1 provides first an Executive Summary of highlights of each of the six volumes, and then goes on to present an overview of the plan, including a discussion of the planning context and strategic approach. Volumes 2, 3, 4, and 5 describe in detail the initiatives proposed. An integral part of each of these volumes is a set of responses to the mission selection criteria questions developed by the Space and Earth Science Advisory Committee. Volume 2, Mission From Planet Earth, describes a strategy for exploring the Moon and Mars and sets forth proposed moderate missions--Lunar Observer and a Mars lander network. Volume 3, Pluto Flyby/Neptune Orbiter, discusses our proposed major new start candidate for the FY 1994 to FY 1998 time frame. Volume 4, Discovery, describes the Near-Earth Asteroid Rendezvous, as well as other candidates for this program of low-cost planetary missions. Volume 5, Toward Other Planetary Systems, describes a major research and analysis augmentation that focuses on extrasolar planet detection and the study of planetary system processes. Finally, Volume 6 summarizes the technology program that the division has structured around these four initiatives.

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NASA NTRS1991

In situ propellant production: Alternatives for Mars exploration

Current planning for the Space Exploration Initiative (SEI) recognizes the need for extraterrestrial resources to sustain long-term human presence and to attain some degree of self-sufficiency. As a practical matter, reducing the need to carry large supplies of propellant from Earth will make space exploration more economical. For nearly every round trip planned with conventional propulsion, the actual payload is only a small fraction - perhaps 10-15 percent - of the mass launched from Earth. The objective of this study was to analyze the potential application for SEI missions of propellants made exclusively from lunar or martian resources. Using such propellants could minimize or eliminate the cost of carrying propellant for surface excursion vehicles and return transfers through two high-energy maneuvers: Earth launch and trans-Mars injection. Certain chemical mono- and bipropellants are candidates for this approach; they could be recovered entirely from in situ resources on the Moon and Mars, without requiring a continuing Earth-based resupply of propellant constituents (e.g., fuel to mix with a locally obtained oxidizer) and, perhaps, with minimal need to resupply consumables (e.g., reagents or catalyst for process reactions). A complete assessment of the performance potential of these propellants must include the requirements for installation, operations, maintenance, and resupply of the chemical processing facility.

Stancati, Michael L.↗
NASA NTRS1992

Future scientific exploration of Taurus-Littrow

The Apollo 17 site was surveyed with great skill and the collected samples have been studied thoroughly (but not completely) in the 20 years since. Ironically, the success of the field and sample studies makes the site an excellent candidate for a return mission. Rather than solving all the problems, the Apollo 17 mission provided a set of sophisticated questions that can be answered only by returning to the site and exploring further. This paper addresses the major unsolved problems in lunar science and points out the units at the Apollo 17 site that are most suitable for addressing each problem. It then discusses how crucial data can be obtained by robotic rovers and human field work. I conclude that, in general, the most important information can be obtained only by human exploration. The paper ends with some guesses about what we could have learned at the Apollo 17 site from a fairly sophisticated rover capable of in situ analyses, instead of sending people.

Taylor, G. Jeffrey↗
NASA NTRS1991

Space transfer concepts and analysis for exploration missions. Implementation plan and element description document. Volume 1: Major trades. Book 1: Draft final

This document presents trade studies and reference concept designs accomplished during a study of Space Transfer Concepts and Analyses for Exploration Missions (STCAEM). This volume contains the major top level trades, level 2 trades conducted in support of NASA's Lunar/Mars Exploration Program Office, and a synopsis of the vehicles for different propulsion systems under trade consideration. The vehicles are presented in more detail in other volumes of this report. Book 1 of Volume 1 covers the following analyses: lunar/Mars commonality trades, lunar/Mars mission operations, and Mars transfer systems.

Source record↗
NASA NTRS1991

Space transfer concepts and analysis for exploration missions. Implementation plan and element description document (draft final). Volume 6: Lunar systems

NASA's two Office of Space Flight (Code M) Space Transfer Vehicle (STV) contractors supported development of Space Exploration Initiative (SEI) lunar transportation concepts. This work treated lunar SEI missions as the far end of a more near-term STV program, most of whose missions were satellite delivery and servicing requirements derived from Civil Needs Data Base (CNDB) projections. Space Transfer Concepts and Analysis for Exploration Missions (STCAEM) began to address the complete design of a lunar transportation system. The following challenges were addressed: (1) the geometry of aerobraking; (2) accommodation of mixed payloads; (3) cryogenic propellant transfer in Low Lunar Orbit (LLO); (4) fully re-usable design; and (5) growth capability. The leveled requirements, derived requirements, and assumptions applied to the lunar transportation system design are discussed. The mission operations section includes data on mission analysis studies and performance parametrics as well as the operating modes and performance evaluations which include the STCAEM recommendations. Element descriptions for the lunar transportation family included are a listing of the lunar transfer vehicle/lunar excursion vehicle (LTV/LEV) components; trade studies and mass analyses of the transfer and excursion modules; advanced crew recovery vehicle (ACRV) (modified crew recovery vehicle (MCRV)) modifications required to fulfill lunar operations; the aerobrake shape and L/D to be used; and some costing methods and results. Commonality and evolution issues are also discussed.

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NASA NTRS1993

Evaluating science return in space exploration initiative architectures

Science is an important aspect of the Space Exploration Initiative, a program to explore the Moon and Mars with people and machines. Different SEI mission architectures are evaluated on the basis of three variables: access (to the planet's surface), capability (including number of crew, equipment, and supporting infrastructure), and time (being the total number of man-hours available for scientific activities). This technique allows us to estimate the scientific return to be expected from different architectures and from different implementations of the same architecture. Our methodology allows us to maximize the scientific return from the initiative by illuminating the different emphases and returns that result from the alternative architectural decisions.

Budden, Nancy Ann↗
NASA NTRS1992

Intelligent robots for planetary exploration and construction

Robots capable of practical applications in planetary exploration and construction will require realtime sensory-interactive goal-directed control systems. A reference model architecture based on the NIST Real-time Control System (RCS) for real-time intelligent control systems is suggested. RCS partitions the control problem into four basic elements: behavior generation (or task decomposition), world modeling, sensory processing, and value judgment. It clusters these elements into computational nodes that have responsibility for specific subsystems, and arranges these nodes in hierarchical layers such that each layer has characteristic functionality and timing. Planetary exploration robots should have mobility systems that can safely maneuver over rough surfaces at high speeds. Walking machines and wheeled vehicles with dynamic suspensions are candidates. The technology of sensing and sensory processing has progressed to the point where real-time autonomous path planning and obstacle avoidance behavior is feasible. Map-based navigation systems will support long-range mobility goals and plans. Planetary construction robots must have high strength-to-weight ratios for lifting and positioning tools and materials in six degrees-of-freedom over large working volumes. A new generation of cable-suspended Stewart platform devices and inflatable structures are suggested for lifting and positioning materials and structures, as well as for excavation, grading, and manipulating a variety of tools and construction machinery.

Albus, James S.↗
NASA NTRS1991

Planning for the Space Exploration Initiative - The nuclear propulsion option

The Space Exploration Initiative includes both lunar and Mars program elements as well as robotic science missions. Space transportation is a primary part of all planning for exploration. The high performance propulsion capabilities of nuclear propulsion offer the potential to reduce substantially the flight times to and from Mars and to reduce the mass launched into low earth orbit.

Bennett, Gary L.↗
NASA NTRS1991

Versatile dynamic isotope power systems for the exploration of space

Dynamic, isotope-heated power systems are needed to carry out the exploration of space and are major elements identified by NASA for the Space Exploration Initiative (SEI). The Dynamic Isotope Power System (DIPS) Demonstration Program is aimed at establishing the advanced technology as well as the system designs and hardware for the SEI and other exploratory missions. Several conceptual designs of DIPS systems have been developed to provide compact, reliable, and long-lived power systems.

Johnson, Richard A.↗
NASA NTRS1993

Mars exploration planning

Mars exploration planning is discussed which is based on three scientific objectives: to understand Mars' geologic and geophysical evolution; to understand the present state and past evolution of Martian climate, and to determine the state of present biological activity and past life. The plan assumes a 25-year planning horizon, from 1995-2020, and includes both broad-scale and local exploration capabilities.

Eppler, Dean B.↗
NASA NTRS1992

Projected NASA power requirements for space science and exploration missions

NASA's Office of Space Science and Applications has recently completed its long-range strategic plan which describes a number of exciting space science missions into the early 21st century. In parallel, NASA's new Office of Exploration has begun defining in more detail the architectures of the Space Exploration Initiative (SEI) for returning to the Moon and going to Mars. Both the space science missions and the SEI missions are dependent upon power sources and energy storage with strong requirements for reliability, long life, ease of assembly, autonomy, and light weight. This paper reviews the currently planned space science and SEI missions and focuses upon the power requirements with a view toward guiding technology developers and power designers.

Gary L Bennett↗
NASA NTRS1992

The Solar/Stellar Coronal Explorer and the Solar/Stellar Coronal Observatory

The Solar/Stellar Coronal Explorer (SSCE) carries six identical Ritchey-Chretien Telescopes of 127 mm aperture each; their images will be recorded by multianode microchannel-array detectors. The mirrors of five of the telescopes are coated with multilayer reflecting structures that select narrow XUV wavelength bands corresponding to strong emission lines emitted by solar or stellar coronal plasmas. Also noted here is a larger explorer mission concept, that of the Solar/Stellar Coronal Observatory, which will undertake more extensive spectroscopic observations.

Walker, Arthur B. C., Jr.↗