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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 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
NASA NTRS1985

Analysis of a method for precisely relating a seafloor point to a distant point on land

A study of the environmental constraints and engineering aspects of the acoustic portion of a system for making geodetic ties between undersea reference points and others on land is described. Important areas in which to make such observations initially would be from the California mainland out to oceanic points seaward of the San Andreas fault, and across the Aleutian Trench. The overall approach would be to operate a GPS receiver in a relative positioning (interferometric) mode to provide the long range element of the baseline determination (10 to 1,000 km) and an array of precision sea floor acoustic transponders to link the locally moving sea surface GPS antenna location to a fixed sea floor point. Analyses of various environmental constrants (tides, waves, currents, sound velocity variations) lead to the conclusion that, if one uses a properly designed transponder having a remotely controllable precise retransmission time delay, and is careful with regard to methods for installing these on the sea floor, one should, in many ocean locations, be able to achieve sub-decimeter overall system accuracy. Achievements of cm accuracy or better will require additional understanding of time and space scales of variation of sound velocity structure in the ocean at relevant locations.

Spiess, F. N.↗
NASA NTRS1987

Fire safety concerns in space operations

This paper reviews the state-of-the-art in fire control techniques and identifies important issues for continuing research, technology, and standards. For the future permanent orbiting facility, the space station, fire prevention and control calls for not only more stringent fire safety due to the long-term and complex missions, but also for simplified and flexible safety rules to accommodate the variety of users. Future research must address a better understanding of the microgravity space environment as it influences fire propagation and extinction and the application of the technology of fire detection, extinguishment, and material assessment. Spacecraft fire safety should also consider the adaptation of methods and concepts derived from aircraft and undersea experience.

Friedman, Robert↗
NASA NTRS1987

The critical role of personality and organizational factors as determinants of reactions to restricted and stressful environments

Research into the impact of personality factors on groups in various settings is reviewed as an introduction to a brief discussion of personality and group behavior research needs relevant to the space program. Significant findings of some earlier research are summarized, and methodological problems are touched on. The study of intergroup and intragroup conflict in a stressful environment, as exemplified particularly by undersea habitats, is seen as being of consequence for long-term space missions. It is concluded that adequate research can only be conducted as an adjunct to data collection from operational stressful environments, and not from laboratory experiments.

Helmreich, Robert L.↗
NASA NTRS1988

Air Revitalization Using Superoxides

Pellets made from powder mixtures of potassium superoxide, KO2, and calcium superoxide, Ca(O2)2, proven markedly superior to pellets of pure KO2 for adding O2 to and removing CO2 from atmospheric-pressure flow of humidified CO2 in He. Superoxides used extensively to supply O2 and scrub CO2 in variety of ambient-pressure life-support applications, including portable self-contained breathing apparatuses, spacecraft, and undersea submersible craft.

Wydeven, Theodore↗
NASA NTRS1988

Subsea approach to work systems development

Self-contained undersea working environments with applications to space station EVA environments are discussed. Physiological limitations include decompression, inert gas narcosis, high-pressure nervous system, gas toxicity, and thermal limitations. Work task requirements include drilling support, construction, inspection, and repair. Work systems include hyperbaric diving, atmospheric work systems, tele-operated work systems, and hybrid systems. Each type of work system is outlined in terms of work capabilities, special interface requirements, and limitations. Various operational philosophies are discussed. The evolution of work systems in the subsea industry has been the result of direct operational experience in a competitive market.

Gernhardt, M. L.↗
NASA NTRS1988

Astronaut and aquanaut performance and adjustment behavioral issues in analogous environments

The utility of analog environments as sources of data for future, long duration space missions is discussed. The undersea habitat is evaluated on a point-by-point basis for similarities and differences with Space Station and a possible lunar base. The comparability of Antarctic wintering-over stations is also considered. Critical issues for research are described, as well as the requirement that participants be involved in the conduct of meaningful work.

Helmreich, Robert L.↗
NASA NTRS1988

Monocoque structure for the SKITTER three-legged walker

The SKITTER 2 design is a monocoque version of the proposed lunar three-legged walker. By the definition of monocoque, the body and legs are a shell with no internal ribbing or supports added for absorbing stresses. The purpose of the monocoque is to encase the elements used for power transmission, power supply, and control of the motion. The material for the structure is a vinyl ester resin, Derakane 8084. This material is easily formable and locally obtainable. The body consists of a hexagonally shaped cylinder with truncated hexagonal pyramids on the top and botton. The legs are eight inch diameter cylinders. The legs are comprised of a tibia section and a femur section. The SKITTER 2 is powered by six actuators which provide linear forces that are transformed into rotary torques by a series of chains and sprockets. The joints connect the femur to the body and the tibia to the femur. Surrounding the joints are flexible rubber hoses that fully encase the chains and sprockets. The SKITTER 2 is capable of walking upside down, righting itself after being overturned, and has the ability to perform in many environments. Applications for this walker include lunar transport or drilling, undersea exploration, and operation in severe surroundings such as arctic temperatures or high radiation.

Bansek, Robert N.↗
NASA NTRS1991

Mesospheric KHI signatures in reconstructed broadband rocket probe data

In an accepted method of measuring D region electron density with a rocket-borne dc-mode Langmuir probe, the resulting fine-structure signal is modified by a high-pass filter. While this form of data has been successfully used for power spectral analysis, it fails to reveal important spatial domain features without further processing. It is demonstrated that the broadband signal can be recovered by use of a digital filter that corrects for the on-board high-pass filter effects. The D-region broadband structure so recovered for a daytime equatorial flight shows variations in electron density consistent with a model of Kelvin-Helmholtz billows, and not consistent with inertial range turbulence. The isolated regions of irregularity are about 100 m thick near an altitude of 75 km, imbedded in a region with a staircase-structure electron density profile with about 200-m steps. Suggestive similarities to a numerical model of KHI are to undersea observations of KHI-caused microstructure are shown.

Parker, Jay W.↗
NASA NTRS1992

Robot Would Assemble Collet/Flexible-Drive Truss Joint

Proposed truss joint designed for assembly by robot. Requires only simple motions of end effector of robot, tolerates relatively large initial misalignment of strut, and assembled with little feedback. Principal features of joint: expanding collet latches it to node ball and collet expanded by flexible drive shaft operated by robot. Developed for Space Station, also used for robotic construction in hazardous or undersea locations.

Evenson, Erik E.↗
NASA NTRS1991

Real-time, interactive, visually updated simulator system for telepresence

Time delays and limited sensory feedback of remote telerobotic systems tend to disorient teleoperators and dramatically decrease the operator's performance. To remove the effects of time delays, key components were designed and developed of a prototype forward simulation subsystem, the Global-Local Environment Telerobotic Simulator (GLETS) that buffers the operator from the remote task. GLETS totally immerses an operator in a real-time, interactive, simulated, visually updated artificial environment of the remote telerobotic site. Using GLETS, the operator will, in effect, enter into a telerobotic virtual reality and can easily form a gestalt of the virtual 'local site' that matches the operator's normal interactions with the remote site. In addition to use in space based telerobotics, GLETS, due to its extendable architecture, can also be used in other teleoperational environments such as toxic material handling, construction, and undersea exploration.

Schebor, Frederick S.↗
NASA NTRS1991

A hazard control system for robot manipulators

A robot for space applications will be required to complete a variety of tasks in an uncertain, harsh environment. This fact presents unusual and highly difficult challenges to ensuring the safety of astronauts and keeping the equipment they depend on from becoming damaged. The systematic approach being taken to control hazards that could result from introducing robotics technology in the space environment is described. First, system safety management and engineering principles, techniques, and requirements are discussed as they relate to Shuttle payload design and operation in general. The concepts of hazard, hazard category, and hazard control, as defined by the Shuttle payload safety requirements, is explained. Next, it is shown how these general safety management and engineering principles are being implemented on an actual project. An example is presented of a hazard control system for controlling one of the hazards identified for the Development Test Flight (DTF-1) of NASA's Flight Telerobotic Servicer, a teleoperated space robot. How these schemes can be applied to terrestrial robots is discussed as well. The same software monitoring and control approach will insure the safe operation of a slave manipulator under teleoperated or autonomous control in undersea, nuclear, or manufacturing applications where the manipulator is working in the vicinity of humans or critical hardware.

Carter, Ruth Chiang↗
NASA NTRS1990

Crew factors in the aerospace workplace

The effects of technological change in the aerospace workplace on pilot performance are discussed. Attention is given to individual and physiological problems, crew and interpersonal problems, environmental and task problems, organization and management problems, training and intervention problems. A philosophy and conceptual framework for conducting research on these problems are presented and two aerospace studies are examined which investigated: (1) the effect of leader personality on crew effectiveness and (2) the working undersea habitat known as Aquarius.

Kanki, Barbara G.↗
NASA NTRS1992

Analog environments in space human factors

An account is given of what has been learned from space analog environments, which mimic such significant features of space as isolation, confinement, risk, and deprivation; emphasis is placed on the especially successful environments constituted by extended submarine research, undersea habitats, and Antarctic station wintering. Attention is also given to the advantages and limitations of the use of analog environments for space human factors research, and possibilities for such research efforts' management.

Connors, Mary M.↗
NASA NTRS1993

Movable Cameras And Monitors For Viewing Telemanipulator

Three methods proposed to assist operator viewing telemanipulator on video monitor in control station when video image generated by movable video camera in remote workspace of telemanipulator. Monitors rotated or shifted and/or images in them transformed to adjust coordinate systems of scenes visible to operator according to motions of cameras and/or operator's preferences. Reduces operator's workload and probability of error by obviating need for mental transformations of coordinates during operation. Methods applied in outer space, undersea, in nuclear industry, in surgery, in entertainment, and in manufacturing.

Diner, Daniel B.↗
NASA NTRS1993

Micro-video display with ocular tracking and interactive voice control

In certain space-restricted environments, many of the benefits resulting from computer technology have been foregone because of the size, weight, inconvenience, and lack of mobility associated with existing computer interface devices. Accordingly, an effort to develop a highly miniaturized and 'wearable' computer display and control interface device, referred to as the Sensory Integrated Data Interface (SIDI), is underway. The system incorporates a micro-video display that provides data display and ocular tracking on a lightweight headset. Software commands are implemented by conjunctive eye movement and voice commands of the operator. In this initial prototyping effort, various 'off-the-shelf' components have been integrated into a desktop computer and with a customized menu-tree software application to demonstrate feasibility and conceptual capabilities. When fully developed as a customized system, the interface device will allow mobile, 'hand-free' operation of portable computer equipment. It will thus allow integration of information technology applications into those restrictive environments, both military and industrial, that have not yet taken advantage of the computer revolution. This effort is Phase 1 of Small Business Innovative Research (SBIR) Topic number N90-331 sponsored by the Naval Undersea Warfare Center Division, Newport. The prime contractor is Foster-Miller, Inc. of Waltham, MA.

Miller, James E.↗
NASA NTRS1993

A prototype case-based reasoning human assistant for space crew assessment and mission management

We present a prototype human assistant system for space crew assessment and mission management. Our system is based on case episodes from American and Russian space missions and analog environments such as polar stations and undersea habitats. The general domain of small groups in isolated and confined environments represents a near ideal application area for case-based reasoning (CBR) - there are few reliable rules to follow, and most domain knowledge is in the form of cases. We define the problem domain and outline a unique knowledge representation system driven by conflict and communication triggers. The prototype system is able to represent, index, and retrieve case studies of human performance. We index by social, behavioral, and environmental factors. We present the problem domain, our current implementation, our research approach for an operational system, and prototype performance and results.

Owen, Robert B.↗
NASA NTRS1995

Engineering development program of a closed aluminum-oxygen semi-cell system for an unmanned underwater vehicle: An update

Most emerging unmanned undersea vehicle (UUV) missions require significantly longer range and endurance than is achievable with existing battery technology. The Aluminum-Oxygen (Al-O2) semi-cell is a candidate technology capable of providing a significant improvement in endurance compared to the silver-zinc battery technology currently used in UUVs and compares favorably to other proposed UUV power systems not only in performance, but also in safety and logistics. An Al-O2 semi-cell system is under development by Loral Defense Systems-Akron (Loral) for the ARPA/Navy 44 in. diameter UUV test vehicle. The power plant consists of a cell stack, gas management, oxygen storage, electrolyte management, coolant and controller subsystems, designed to replace the existing silver-zinc battery and meet existing weight, volume, electrical and thermal requirements, therefore minimizing modifications to the UUV. A detailed system design is complete. A component and material endurance test to evaluate compatibility and reliability of various material arid components is complete. Sub scale (Short stack) system testing is completed. A full-scale demonstration unit is now under construction in the second half of 1995. The full scale demonstration test will simulate environmental conditions of the operational system. This paper summarizes the results of the extensive short stack and endurance test programs, describes the plan for full-scale testing, and concludes with a brief discussions of future directions for this technology. This program is sponsored by ARPA Maritime Systems Technology Office under NASA contract NAS3-26715.

Gregg, Dane W.↗
NASA NTRS1995

Shielded, Automated Umbilical Mechanism

Umbilical mechanism automatically connects and disconnects various fluid couplings and/or electrical contacts while shielding mating parts from debris. Reacts mating and demating loads internally, without additional supporting structures. All functions - extension of plug, mating, and movement of debris shields - actuated by single motor. If mechanism jams or fails at any point in sequence, override feature in drive train allows manual operation. Designed for service in outer space, where its shields protect against micrometeoroids, debris, ultraviolet radiation, and atomic oxygen. Used on Earth to connect or disconnect fluid or electrical utilities in harsh environments like those of nuclear powerplants or undersea construction sites, or in presence of radioactive, chemical, or biological hazards, for example.

Barron, Daniel R.↗