Keywords: man environment interactions; environment pollution; space pollution; earth orbital environments; orbital debris; pollution; space debris
Abstract: Before 1990, knowledge of the orbital debris environment could be broken down into 2 size regimes. For low Earth orbiting objects larger than 10-20 cm in diameter, the U.S. Space Command maintains a catalog which includes debris as well as satellites and rocket bodies. The diameter limit is the result of the wavelengths and sensitivities of the radars used. To better characterized the orbital debris environment, NASA began using the DOD-funded Haystack radar; in return, NASA paid for the construction of the Haystack auxiliary radar. The Haystack Orbital Debris Data Review Panel was established in 1996 to consider the adequacy of the data on orbital debris gathered over the past several years with the Haystack radar, and the accuracy of the methods used to estimate the flux vs. size relationship for this debris. This paper discusses specific issues addressed by the Panel, interpretation of these issues, the current status of the measurement and analysis program NASA is conducting, the statistical aspects in use of the Haystack radar data, the Panel's conclusions on these issues, and recommendations.
Keywords: motion, motion perception, perception, control, adaptive control
Abstract: The purpose of this report is to identify the essential characteristics of goal-directed whole-body motion. The report is organized into three major sections. Section 2 reviews general themes from ecological psychology and control-systems engineering that are relevant to the perception and control of whole-body motion. These themes provide an organizational framework for analyzing the complex and interrelated phenomena that are the defining characteristics of whole-body motion. Section 3 applies the organizational framework from the first section to the problem of perception and control of aircraft motion. This is a familiar problem in control-systems engineering and ecological psychology. Section 4 examines an essential but generally neglected aspect of vehicular control: coordination of postural control and vehicular control. To facilitate presentation of this new idea, postural control and its coordination with vehicular control are analyzed in terms of conceptual categories that are familiar in the analysis of vehicular control.
Keywords: motion, motion perception, perception, control, adaptive control
Abstract: This report reviews the operational demands made of a Shuttle pilot or commander within the context of a proven empirical methodology for describing human sensorimotor performance and whole-body coordination in mechanically and perceptually complex environments. The conclusions of this review pertain to a) methods for improving our understanding of the psychophysics and biomechanics of visual/manual control and whole-body coordination in space vehicle cockpits. b) the application of scientific knowledge about human perception and performance in dynamic inertial conditions to the development of technology, procedures, and training for personnel in space vehicle cockpits. c) recommendations for mitigation of safety and reliability concerns about human performance in space vehicle cockpits. d) in-flight evaluation of flight crew performance during nominal and off-nominal launch and reentry scenarios.
Keywords: man-computer interface; computer programs; software engineering; software tools; computer systems design
Abstract: The characteristics of this field guide approach address the problems of designing innovative software to support user tasks. The requirements for novel software are difficult to specify a priori, because there isn't sufficient understanding of how the user's tasks should be supported, and there aren't obvious pre-existing design solutions. When the design team is in unfamiliar territory, care must be taken to avoid rushing into detailed design, requirements specifications, or implementing the wrong product. The challenge is to get the right design and requirements in an efficient, cost-effective manner. This document's purpose is to describre the methods we are using to design human interactions with intelligent systems that support Space Shuttle flight controllers in the Mission Control Center. Although these software systems usually have some intelligent freatures, the design challenges arise primarily from the innovation needed in the software design. While these methods are tailored to our specific context, they should be extensible, and helpful to designers of human interaction with other types of automated systems. We review the unique features of this context so you can determine how to apply these methods to your project. Throughout this field guide, we discuss goals of the design methods. This should help designers understand how a specific method might need to be adapted to the project at hand.
Keywords: Hubble Space Telescope, solar arrays, photogrammetry, solar dynamic power systems
Abstract: This report documents the photogrammetric assessment of the Hubble Space Telescope (HST) solar arrays conducted by the NASA Johnson Space Center Image Science and Analysis Group during the second Servicing Mission (SM-2) on STS-82 in February of 1997. Two types of solar array analyses were conducted during the mission using Space shuttle payload bay video: (1) measurement of solar array motion due to induced loads, and (2) measurement of solar array static or geometric twist caused by the cumulative array loading. The report describes premission planning and analysis technique development activities conducted to acquire and analyze solar array imagery data during SM-2. This includes analysis of array motion obtained during SM-1 as a proof-of-concept of the SM-2 measurement techniques. The report documents the results of real-time analysis conducted during the mission and subsequent analysis conducted post-flight. This report also provides a summary of lessons learned on solar array imagery analysis from SM-2 and recommendations for future on-orbit measurements applicable to HST SM-3 and to the International Space Station. This work was performed under the direction of the Goddard Space Flight Center HST Flight Systems and Servicing Project.
Keywords: aerogel, space debris, cosmic dust, cometary atmospheres, deceleration, hypervelocity impact, impact melts
Abstract: Recent impact experiments conducted at the Johnson Space Center supported a space-exposed flight instrument called the orbital debris collector (ODC) to see whether SiO2 aerogel performed adequatedly as a collector to capture cosmic dust particles and/or manmade debris, or whether additional develpment is needed. The first ODC was flown aboard the Mir for 18 months, while the second will be flown aboard a spacecraft (Stardust, to be launche in 1999) that will encounter the comet Wild 2 and return to Earth. Aerogels are highly porous materials that decelerate high-velocity particles without substantial melting or modifications to the particle components. In other denser materials, these particles would melt or vaporize upon impact. The experimental data in this report must be considered somewhat qualitative because they are characterized by substantial, if not intolerable, scatter, possibly caused by experimental difficulties in duplicating given setes of initial impact conditions. Therefore, this report is a chronological guide of our attempts, difficulties, progress, and evaluations for future tests.
Keywords: manned Mars missions, Mars, extraterrestrial resources, utilization, site selection
Abstract: As a planet with striking similarities to Earth, Mars is an important focus for scientific research aimed at understanding the processes of planetary evolution and the formation of our solar system. Fortunately, Mars is also a planet with abundant natural resources, including accessible materials that can be used to support human life and to sustain a self-sufficient martian outpost. Resources required include water, breathable air, food, shelter, energy, and fuel. Through a mission design based on in situ resource development, we can establish a permanent outpost on Mars beginning with the first manned mission. This paper examines the potential for supporting the first manned mission with the objective of acheiveing self-suffeiciency throuhg well understood resource development and a program of rigorous scientific research aimed at extending that capability. We examine the potential for initially extracting critical resources from the martian environment, and discuss the scientific investigations required to identify additional resources in the atmosphere, on the surface, and within the subsurface. We also discuss our current state of knowledge of Mars, technical considerations of resource utilization, and using unmanned missions' data for selecting an optimal site. The primary goal of achieving self-sufficiency on Mars would accelerate the development of human colonization beyond Earth, while providing a robust and permanent martian base from which humans can explore and conduct long-term research on planetary evolution, the solar system, and life itself.
Keywords: exercise physiology, physical exercise, weightlessness, muscular strength, bones
Abstract: This demonstration project assessed the crew members' compliance to a portion of the exercise countermeasures planned for use on board the International Space Station (ISS) and the outcomes of their performing these countermeasures. Although these countermeasures have been used separately in other projects and investigations, this was the first time they'd been used together for an extended period (60 days) in an investigation of this nature. Crew members exercised every day for six days, alternating every other day between aerobic and resistive exercise, and rested on the seventh day. On the aerobic exercise days, subjects exercised on an electronically braked cycle ergometer using a protocol that has been previously shown to maintain aerobic capacity in subjects exposed to a space flight analogue. On the resistive exercise days, crew members performed five major multijoint resistive exercises in a concentric mode, targeting those muscle groups and bones we believe are most severely affected by space flight. The subjects favorably tolerated both exercise protocols, with a 98% compliance to aerobic exercise prescription and a 91% adherence to the resistive exercise protocol. After 60 days, the crew members improved their peak aerobic capacity by an average 7%, and strength gains were noted in all subjects. These results suggest that these exercise protocols can be performed during ISS, lunar, and Mars missions, although we anticipate more frequent bouts with both protocols for long-duration spaceflight. Future projects should investigate the impact of increased exercise duration and frequency on subject compliance, and the efficacy of such exercise prescriptions.
Keywords: flow measurement, flow, axisymmetric flow, parabolic bodies, shock layers, viscous flow, heat flux
Abstract: A technique is implemented for computing hypersonic aeroheating, shear stress, and other flow properties on the windward side of a three-dimensional (3D) blunt body. The technique uses a 2D/axisymmetric flow solver modified by scale factors for a corresponding equivalent axisymmetric body. Examples are given in which a 2D solver is used to calculate the flow at selected meridional planes on elliptic paraboloids in reentry flight. The report describes the equations and the codes used to convert the body surface parameters into input used to scale the 2D viscous shock layer equations in the axisymmetric viscous shock layer code. Very good agreement is obtained with solutions to finite rate chemistry 3D thin viscous shock layer equations for a finite rate catalytic body.
Keywords: Mars, exploration, human, space transportation, propulsion
Abstract: This Addendum to the Mars Reference Mission was developed as a companion document to the NASA Special Publication 6107, "Human Exploration of Mars: The Reference Mission of the NASA Mars Exploration Study Team." It summarizes changes and updates to the Mars Reference Mission that were developed by the Agencywide Exploration Team since the final draft of SP 6107 was printed in early 1998. The Reference Mission is a tool used by the exploration community to compare and evaluate approaches to mission and system concepts that could be used for human missions to Mars. It is intended to identify and clarify system drivers, significant sources of cost, performance, risk, and schedule variation. Several alternative scenarios, employing different technical approaches to solving mission and technology challenges, are discussed in this Addendum. Comparing alternative approaches provides the basis for continual improvement to technology investment plans and a general understanding of future human missions to Mars. The Addendum represents a snapshot of work in progress in support of planning future human exploration missions through May 1998.
Keywords: exercise physiology, laboratories, physiological tests
Abstract: This manual describes the laboratory methods used to collect flight crew physiology performance data at the Johnson Space Center. The Exercise Countermeasures Project Laboratory is a standard physiology laboratory; only the application to the study of human physiological adaptations to space flight is unique. In the absence of any other recently published laboratory manual, this manual should be a useful document for the staffs and students of other laboratories.
Keywords: Research Projects, Research and Development, NASA Programs, Technology Utilization, Space Technology Experiments
Abstract: This report highlights key projects and technologies at Johnson Space Center for1997. The report focuses on the commercial potential of the projects and technologies and is arranged by CorpTech Major Products Groups. Emerging technologies in these major disciplines are summarized: solar system sciences, life sciences, technology transfer, computer sciences, space technology, and human support technology. These NASA advances have a range of potential commercial applications, from a school internet manager for networks to a liquid metal mirror for optical measurements. For general commercial information or commercialization information about a specific tehcnology, contact the NASA JSC Office of Technology Transfer and Commercialization at: NASA JSC, mail code HA, 2101 NASA Rd 1, Houston, TX, 77058-3696; Tel: (281) 483-3809; Fax: (281) 244-8452; E-mail: email@example.com; Web page: http://technology.jsc.nasa.gov
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