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At least 19 records

Development of a test protocol for evaluating EVA glove performance

Testing gloved hand performance involves work from several disciplines. Evaluations performed in the course of reenabling a disabled hand, designing a robotic end effector or master controller, or hard-suit design have all yielded relevant information, and, in most cases, produced performance test methods. Most times, these test methods have been primarily oriented toward their parent discipline. For space operations, a comparative test which would provide a way to quantify pressure glove and end effector performance would be useful in dividing tasks between humans and robots. Such a test would have to rely heavily on sensored measurement, as opposed to questionnaires, to produce relevant data. However, at some point human preference would have to be taken into account. This paper presents a methodology for evaluating gloved hand performance which attempts to respond to these issues. Glove testing of a prototype glove design using this method is described.

Hinman, Elaine M.↗

The use of automation and robotic systems to establish and maintain lunar base operations

Robotic systems provide a means of performing many of the operations required to establish and maintain a lunar base. They form a synergistic system when properly used in concert with human activities. This paper discusses the various areas where robotics and automation may be used to enhance lunar base operations. Robots are particularly well suited for surface operations (exterior to the base habitat modules) because they can be designed to operate in the extreme temperatures and vacuum conditions of the Moon (or Mars). In this environment, the capabilities of semi-autonomous robots would surpass that of humans in all but the most complex tasks. Robotic surface operations include such activities as long range geological and mineralogical surveys with sample return, materials movement in and around the base, construction of radiation barriers around habitats, transfer of materials over large distances, and construction of outposts. Most of the above operations could be performed with minor modifications to a single basic robotic rover. Within the lunar base habitats there are a few areas where robotic operations would be preferable to human operations. Such areas include routine inspections for leakage in the habitat and its systems, underground transfer of materials between habitats, and replacement of consumables. In these and many other activities, robotic systems will greatly enhance lunar base operations. The robotic systems described in this paper are based on what is realistically achievable with relatively near term technology. A lunar base can be built and maintained if we are willing.

Petrosky, Lyman J.↗

The Interstellar Conspiracy

If we were designing a human-carrying starship that could be launched in the not-too-distant future, it would almost certainly not use a warp drive to instantaneously bounce around the universe, as is done in Isaac Asimov's classic Foundation series or in episodes of Star Trek or Star Wars. Sadly, those starships that seem to be within technological reach could not even travel at high relativistic speeds, as does the interstellar ramjet in Poul Anderson's Tau Zero. Warp-speeds seem to be well outside the realm of currently understood physical law; proton-fusing ramjets may never be technologically feasible. Perhaps fortunately in our terrorist-plagued world, the economics of antimatter may never be attractive for large-scale starship propulsion. But interstellar travel will be possible within a few centuries, although it will certainly not be as fast as we might prefer. If humans learn how to hibernate, perhaps we will sleep our way to the stars, as do the crew in A. E. van Vogt's Far Centaurus. However, as discussed in a landmark paper in The Journal of the British Interplanetary Society, the most feasible approach to transporting a small human population to the planets (if any) of Alpha Centauri is the worldship. Such craft have often been featured in science fiction. See for example Arthur C. Clarke's Rendezvous with Rama, and Robert A. Heinlein's Orphans of the Sky. Worldships are essentially mobile versions of the O Neill free-space habitats. Constructed mostly from lunar and/or asteroidal materials, these solar-powered, multi-kilometer-dimension structures could house 10,000 to 100,000 humans in Earth-approximating environments. Artificial gravity would be provided by habitat rotation, and cosmic ray shielding would be provided by passive methods, such as habitat atmosphere and mass shielding, or magnetic fields. A late 21st century space-habitat venture might support itself economically by constructing large solar-powered satellites to beam energy back to Earth.

Johnson, Les↗

The structure and formation of natural categories

Categorization and concept formation are critical activities of intelligence. These processes and the conceptual structures that support them raise important issues at the interface of cognitive psychology and artificial intelligence. The work presumes that advances in these and other areas are best facilitated by research methodologies that reward interdisciplinary interaction. In particular, a computational model is described of concept formation and categorization that exploits a rational analysis of basic level effects by Gluck and Corter. Their work provides a clean prescription of human category preferences that is adapted to the task of concept learning. Also, their analysis was extended to account for typicality and fan effects, and speculate on how the concept formation strategies might be extended to other facets of intelligence, such as problem solving.

Fisher, Douglas↗

NASA'S concept for a human mission to a near-earth asteroid : preference tradeoffs for the surveyor decision problem

NASA's recent attention and interest in sending a human mission to land on a Near-Earth asteroid raised the question of whether to first send a robotic surveyor. This paper describes a Bayesian approach for comparing the value and cost-risk tradeoffs of sending (versus not sending) surveyor missions prior to a human mission. A multiattribute decision analysis approach was used to account for both mission value and cost in each of 27 hypothetical risk-attitude cases corresponding to an emphasis on mission value; equal priority between mission value and cost; and an emphasis on cost. The decisions implied by the different strategic viewpoints are described.

Smith, Jeffrey H.↗

Critical Questions for Space Human Factors

Traditional human factors contributions to NASA's crewed space programs have been rooted in the classic approaches to quantifying human physical and cognitive capabilities and limitations in the environment of interest, and producing recommendations and standards for the selection or design of mission equipment. Crews then evaluate the interfaces, displays, or equipment, and with the assistance of human factors experts, improvements are made as funds, time, control documentation, and weight allow. We have come a long way from the early spaceflight days, where men with the ' right stuff were the solution to operating whatever equipment was given to them. The large and diverse Shuttle astronaut corps has impacted mission designs to accommodate a wide range of human capabilities and preferences. Yet with existing long duration experience, we have seen the need to address a different set of dynamics when designing for optimal crew performance: critical equipment and mission situations degrade, and human function changes with mission environment, situation, and duration. Strategies for quantifying the critical nature of human factors requirements are being worked by NASA. Any exploration-class mission will place new responsibilities on mission designers to provide the crew with the information and resources to accomplish the mission. The current duties of a Mission Control Center to monitor system status, detect degradation or malfunction, and provide a proven solution, will need to be incorporated into on-board systems to allow the crew autonomous decision-making. The current option to resupply and replace mission systems and resources, including both vehicle equipment and human operators, will be removed, so considerations of maintenance, onboard training, and proficiency assessment are critical to providing a self-sufficient crew. As we 'move in' to the International Space Station, there are tremendous opportunities to investigate our ability to design for autonomous crews. Yet prioritizing the research that can and should be done by NASA will be based on the critical nature of the issues, and the impact of the individual research questions on mission design. The risks to crew health and safety associated with answering critical human factors issues must be properly included and communicated in order to support the Agency's decisions regarding future space programs.

Woolford, Barbara↗

Extravehicular Activity Testing in Analog Environments: Evaluating the Effects of Center of Gravity and Environment on Human Performance

The EVA Physiology, Systems and Performance (EPSP) Project is performing tests in different analog environments to understand human performance during Extravehicular Activity (EVA) with the aim of developing more safe and efficient systems for lunar exploration missions and the Constellation Program. The project is characterizing human EVA performance in studies using several test beds, including the underwater NASA Extreme Environment Mission Operations (NEEMO) and Neutral Buoyancy Laboratory (NBL) facilities, JSC fs Partial Gravity Simulator (POGO), and the NASA Reduced Gravity Office (RGO) parabolic flight aircraft. Using these varied testing environments, NASA can gain a more complete understanding of human performance issues related to EVA and the limitations of each testing environment. Tests are focused on identifying and understanding the EVA system factors that affect human performance such as center of gravity (CG), inertial mass, ground reaction forces (GRF), suit weight, and suit pressure. The test results will lead to the development of lunar EVA systems operations concepts and design requirements that optimize human performance and exploration capabilities. METHODS: Tests were conducted in the NBL and during NEEMO missions in the NOAA Aquarius Habitat. A reconfigurable back pack with repositionable mass was used to simulate Perfect, Low, Forward, High, Aft and NASA Baseline CG locations. Subjects performed simulated exploration tasks that included ambulation, kneel and recovery, rock pick-up, and shoveling. Testing using POGO, that simulates partial gravity via pneumatic weight offload system and a similar reconfigurable rig, is underway for a subset of the same tasks. Additionally, test trials are being performed on the RGO parabolic flight aircraft. Subject performance was assessed using a modified Cooper-Harper scale to assess operator compensation required to achieve desired performance. All CG locations are based on the assumption of a standardized 6 ft 180 lb subject. RESULTS: The modified Cooper-Harper Scale assesses desired task performance described as performance in a reduced gravity environment as compared to a 1G environment. Modified Cooper-Harper ratings of . 3 indicate no improvements are needed, ratings of 4-6 indicate improvements are desirable, and ratings . 7 indicate improvements are mandatory. DISCUSSION: Differences were noted in suited CH results based on environment at the same CG and suit pressure. Additionally, results suggest that CG location affects unsuited human performance. Subjects preferred locations near their natural CG over those that are high, aft, or a combination of high and aft. Further testing and analyses are planned to compare these unsuited results to suited performance.

Gernhardt, M.L.↗

Where do we locate the moon base

Because the lunar polar regions permit continuous solar energy collection and adjacent cryogenic temperature, they may be the preferred sites for early human occupation and use of the moon. If permafrost exists in the polar shaded regions, this preference will become dominant. Though not ideal from the point of view of all-sky coverage for astronomical observations, and also possibly subject to terminator-plane particle hazes near the surface, polar sites (especially the south polar region) may offer enough advantages (e.g., constant cryogenic telescope environments and unlimited tracking time) to be preferred sites for the first lunar observatories.

Burke, J. D.↗

Automation effects in a stereotypical multiloop manual control system

The increasing reliance of state-of-the art, high performance aircraft on high authority stability and command augmentation systems, in order to obtain satisfactory performance and handling qualities, has made critical the achievement of a better understanding of human capabilities, limitations, and preferences during interactions with complex dynamic systems that involve task allocation between man and machine. An analytical and experimental study has been undertaken to investigate human interaction with a simple, multiloop dynamic system in which human activity was systematically varied by changing the levels of automation. Task definition has led to a control loop structure which parallels that for any multiloop manual control system, and may therefore be considered a stereotype.

Hess, R. A.↗

Opportunities for nutritional amelioration of radiation-induced cellular damage

The closed environment and limited evasive capabilities inherent in space flight cause astronauts to be exposed to many potential harmful agents (chemical contaminants in the environment and cosmic radiation exposure). Current power systems used to achieve space flight are prohibitively expensive for supporting the weight requirements to fully shield astronauts from cosmic radiation. Therefore, radiation poses a major, currently unresolvable risk for astronauts, especially for long-duration space flights. The major detrimental radiation effects that are of primary concern for long-duration space flights are damage to the lens of the eye, damage to the immune system, damage to the central nervous system, and cancer. In addition to the direct damage to biological molecules in cells, radiation exposure induces oxidative damage. Many natural antioxidants, whether consumed before or after radiation exposure, are able to confer some level of radioprotection. In addition to achieving beneficial effects from long-known antioxidants such as vitamins E and C and folic acid, some protection is conferred by several recently discovered antioxidant molecules, such as flavonoids, epigallocatechin, and other polyphenols. Somewhat counterintuitive is the protection provided by diets containing elevated levels of omega-3 polyunsaturated fatty acids, considering they are thought to be prone to peroxidation. Even with the information we have at our disposal, it will be difficult to predict the types of dietary modifications that can best reduce the risk of radiation exposure to astronauts, those living on Earth, or those enduring diagnostic or therapeutic radiation exposure. Much more work must be done in humans, whether on Earth or, preferably, in space, before we are able to make concrete recommendations.

Review↗

Piezoelectric Vibrational and Acoustic Alert for a Personal Communication Device

An alert apparatus for a personal communication device includes a mechanically prestressed piezoelectric wafer positioned within the personal communication device and an alternating voltage input line coupled at two points of the wafer where polarity is recognized. The alert apparatus also includes a variable frequency device coupled to the alternating voltage input line, operative to switch the alternating voltage on the alternating voltage input line at least between an alternating voltage having a first frequency and an alternating voltage having a second frequency. The first frequency is preferably sufficiently high so as to cause the wafer to vibrate at a resulting frequency that produces a sound perceptible by a human ear, and the second frequency is preferably sufficiently low so as to cause the wafer to vibrate at a resulting frequency that produces a vibration readily felt by a holder of the personal communication device.

Stanley E Woodard↗

Comparison of voice types for helicopter voice warning systems

Three related studies were conducted to compare different types of human voice warnings. In the first study, a comparison of three LPC-encoded voices, human female, human male, and phoneme-synthesized, by the criteria of pilot flight task performance showed no differences due to the voice type. In the second study, pilots' preferences were investigated, by comparing preference for direct synthesized speech to the LPC-encoded human female speech and to LPC-encoded synthesized speech. Most pilots were found to prefer direct synthesized speech over both LPC-encoded human female speech and the LPC-encoded synthesized speech. In the third study, phonetically balanced (PB) words heard in simulated helicopter noise were used to compare the intelligibility of direct synthesized and LPC-encoded phoneme-synthesized speech types. PB word intelligibility was found to be better for direct synthesized speech than for the LPC-encodes synthesized speech.

Simpson, C. A.↗

JIGSAW: Preference-directed, co-operative scheduling

Techniques that enable humans and machines to cooperate in the solution of complex scheduling problems have evolved out of work on the daily allocation and scheduling of Tactical Air Force resources. A generalized, formal model of these applied techniques is being developed. It is called JIGSAW by analogy with the multi-agent, constructive process used when solving jigsaw puzzles. JIGSAW begins from this analogy and extends it by propagating local preferences into global statistics that dynamically influence the value and variable ordering decisions. The statistical projections also apply to abstract resources and time periods--allowing more opportunities to find a successful variable ordering by reserving abstract resources and deferring the choice of a specific resource or time period.

Linden, Theodore A.↗

An error-resistant linguistic protocol for air traffic control

The research results described here are intended to enhance the effectiveness of the DATALINK interface that is scheduled by the Federal Aviation Administration (FAA) to be deployed during the 1990's to improve the safety of various aspects of aviation. While voice has a natural appeal as the preferred means of communication both among humans themselves and between humans and machines as the form of communication that people find most convenient, the complexity and flexibility of natural language are problematic, because of the confusions and misunderstandings that can arise as a result of ambiguity, unclear reference, intonation peculiarities, implicit inference, and presupposition. The DATALINK interface will avoid many of these problems by replacing voice with vision and speech with written instructions. This report describes results achieved to date on an on-going research effort to refine the protocol of the DATALINK system so as to avoid many of the linguistic problems that still remain in the visual mode. In particular, a working prototype DATALINK simulator system has been developed consisting of an unambiguous, context-free grammar and parser, based on the current air-traffic-control language and incorporated into a visual display involving simulated touch-screen buttons and three levels of menu screens. The system is written in the C programming language and runs on the Macintosh II computer. After reviewing work already done on the project, new tasks for further development are described.

Cushing, Steven↗

Advanced Structural and Inflatable Hybrid Spacecraft Module

An inflatable module comprising a structural core and an inflatable shell, wherein the inflatable shell is sealingly attached to the structural core. In its launch configuration, the wall thickness of the inflatable shell is collapsed by vacuum. Also in this configuration, the inflatable shell is collapsed and efficiently folded around the structural core. Upon deployment, the wall thickness of the inflatable shell is inflated; whereby the inflatable shell itself, is thereby inflated around the structural core, defining therein a large enclosed volume. A plurality of removable shelves are arranged interior to the structural core in the launch configuration. The structural core also includes at least one longeron that, in conjunction with the shelves, primarily constitute the rigid, strong, and lightweight load-bearing structure of the module during launch. The removable shelves are detachable from their arrangement in the launch configuration so that, when the module is in its deployed configuration and launch loads no longer exist, the shelves can be rearranged to provide a module interior arrangement suitable for human habitation and work. In the preferred embodiment, to provide efficiency in structural load paths and attachments, the shape of the inflatable shell is a cylinder with semi-toroidal ends.

Schneider, William C.↗

Inflatable Vessel and Method

An inflatable module comprising a structural core and an inflatable shell, wherein the inflatable shell is sealingly attached to the structural core. In its launch or pre-deployed configuration, the wall thickness of the inflatable shell is collapsed by vacuum. Also in this configuration, the inflatable shell is collapsed and efficiently folded around the structural core. Upon deployment, the wall thickness of the inflatable shell is inflated; whereby the inflatable shell itself, is thereby inflated around the structural core, defining therein a large enclosed volume. A plurality of removable shelves are arranged interior to the structural core in the launch configuration. The structural core also includes at least one longeron that, in conjunction with the shelves, primarily constitute the rigid, strong, and lightweight load-bearing structure of the module during launch. The removable shelves are detachable from their arrangement in the launch configuration so that, when the module is in its deployed configuration and launch loads no longer exist, the shelves can be rearranged to provide a module interior arrangement suitable for human habitation and work. In the preferred embodiment, to provide efficiency in structural load paths and attachments, the shape of the inflatable shell is a cylinder with semi-toroidal ends.

Raboin, Jasen L.↗

Eating in space--from an astronaut's perspective

Food systems and meal components are constantly under review and development at the National Aerospace and Space Administration. The goal of this work is to generate a diet that meets the nutrient requirements of astronauts and satiates them. The constraints involved in shorter- and longer-term missions are described. The insight provided by observations of astronauts from the Skylab and Shuttle eras will allow researchers to consider the fact that, for any nutritional regimen to work, it must consider the limitations and taste buds of the individuals involved. Otherwise, the best diet design generated by their work may never be consumed.

Review, Tutorial↗

Suggestions for crops grown in controlled ecological life-support systems, based on attractive vegetarian diets

Assuming that crops grown in controlled ecological life-support systems (CELSS) should provide a basis for meals that are both nutritious and attractive (to taste and vision), and that CELSS diets on the moon or Mars or in space-craft during long voyages will have to be mostly vegetarian, a workshop was convened at the Johnson Space Center, Houston, Texas, U.S.A. on 19 to 21 January, 1994. Participants consisted of trained nutritionists and others; many of the approximately 18 presenters who discussed possible diets were practicing vegetarians, some for more than two decades. Considering all the presentations, seven conclusions (or points for discussion) could be formulated: nutritious vegetarian diets are relatively easily to formulate, vegetarian diets are healthy, variety is essential in vegetarian diets, some experiences (e.g., Bios-3 and Biosphere 2) are relevant to planning of CELSS diets, physical constraints will limit the choice of crops, a preliminary list of recommended crops can be formulated, and this line of research has some potential practical spinoffs. The list of crops and the reasons for including specific crops might be of interest to professionals in the field of health and nutrition as well as to those who are designing closed ecological systems.

NASA Program CELSS↗