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At least 163 records · Page 9

Large space reflector technology on the Space Station

This paper discusses the role of the Space Station in the evolutionary development of large space reflector technology and the accommodation of mission systems which will apply large space reflectors during the late 1990s and the early part of the next century. Reflectors which range from 10 to 100 meters in size and which span the electromagnetic spectrum for applications that include earth communications, earth observations, astrophysics and solar physics, and deep space communications are discussed. The role of the Space Station in large space reflector technology development and system performance demonstration is found to be critical; that role involves the accommodation of a wide variety of technology demonstrations and operational activities on the Station, including reflector deployment and/or assembly, mechanical performance verification and configuration refinement, systematic diagnostics of reflector surfaces, structural dynamics and controls research, overall system performance characterization and modification (including both radio frequency field pattern measurements and required end-to-end system demonstrations), and reflector-to-spacecraft integration and staging. A unique facility for Space Station-based, large space reflector research and development is proposed. A preliminary concept for such a Space Station-based Large Space Reflector Facility (LSRF) is described.

Mankins, J. C.↗

A computer program for model verification of dynamic systems

Dynamic model verification is the process whereby an analytical model of a dynamic system is compared with experimental data, and then qualified for future use in predicting system response in a different dynamic environment. There are various ways to conduct model verification. The approach adopted in MOVER II employs Bayesian statistical parameter estimation. Unlike curve fitting whose objective is to minimize the difference between some analytical function and a given quantity of test data (or curve), Bayesian estimation attempts also to minimize the difference between the parameter values of that function (the model) and their initial estimates, in a least squares sense. The objectives of dynamic model verification, therefore, are to produce a model which: (1) is in agreement with test data, (2) will assist in the interpretation of test data, (3) can be used to help verify a design, (4) will reliably predict performance, and (5) in the case of space structures, facilitate dynamic control.

Chrostowski, J. D.↗

Technologies applicable to space tethers

An investigation is presented of technologies which have been accumulated over the years, both on Earth and in space, dealing with tethers, ropes and cables. Many of these technologies can be applied, with modification, to both on-going and future space tether research and demonstration missions. The major areas of tether research and technology developments presented include multimegawatt power transmission, materials and structures, dynamics and control, environmental interactions, and in-space operations. These major topical areas are presented within the context of their associated research program or study.

Baracat, William A.↗

Space station systems: A bibliography with indexes (supplement 7)

This bibliography lists 1,158 reports, articles, and other documents introduced into the NASA scientific and technical information system between January 1, 1988 and June 30, 1988. Its purpose is to provide helpful information to researchers, designers and managers engaged in Space Station technology development and mission design. Coverage includes documents that define major systems and subsystems related to structures and dynamic control, electronics and power supplies, propulsion, and payload integration. In addition, orbital construction methods, servicing and support requirements, procedures and operations, and missions for the current and future Space Station are included.

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Technology for large space systems: A bibliography with indexes (supplement 20)

This bibliography lists 694 reports, articles, and other documents introduced into the NASA Scientific and Technical Information System between July, 1988 and December, 1988. Its purpose is to provide helpful information to the researcher or manager engaged in the development of technologies related to large space systems. Subject areas include mission and program definition, design techniques, structural and thermal analysis, structural dynamics and control systems, electronics, advanced materials, assembly concepts, and propulsion.

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Space Station Systems: a Bibliography with Indexes (Supplement 8)

This bibliography lists 950 reports, articles, and other documents introduced into the NASA scientific and technical information system between July 1, 1989 and December 31, 1989. Its purpose is to provide helpful information to researchers, designers and managers engaged in Space Station technology development and mission design. Coverage includes documents that define major systems and subsystems related to structures and dynamic control, electronics and power supplies, propulsion, and payload integration. In addition, orbital construction methods, servicing and support requirements, procedures and operations, and missions for the current and future Space Station are included.

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Space station systems: A bibliography with indexes (supplement 9)

This bibliography lists 1,313 reports, articles, and other documents introduced into the NASA scientific and technical information system between January 1, 1989 and June 30, 1989. Its purpose is to provide helpful information to researchers, designers and managers engaged in Space Station technology development and mission design. Coverage includes documents that define major systems and subsystems related to structures and dynamic control, electronics and power supplies, propulsion, and payload integration. In addition, orbital construction methods, servicing and support requirements, procedures and operations, and missions for the current and future Space Station are included.

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Space station systems: A bibliography with indexes (supplement 10)

This bibliography lists 1,422 reports, articles, and other documents introduced into the NASA scientific and technical information system between July 1, 1989 and December 31, 1989. Its purpose is to provide helpful information to researchers, designers and managers engaged in Space Station technology development and mission design. Coverage includes documents that define major systems and subsystems related to structures and dynamic control, electronics and power supplies, propulsion, and payload integration. In addition, orbital construction methods, servicing and support requirements, procedures and operations, and missions for the current and future Space Station are included.

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Technology for large space systems: A bibliography with indexes (supplement 22)

This bibliography lists 1077 reports, articles, and other documents introduced into the NASA Scientific and Technical Information System between July 1, 1989 and December 31, 1989. Its purpose is to provide helpful information to the researcher or manager engaged in the development of technologies related to large space systems. Subject areas include mission and program definition, design techniques, structural and thermal analysis, structural dynamics and control systems, electronics, advanced materials, assembly concepts, and propulsion.

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IMAT graphics manual

The Integrated Multidisciplinary Analysis Tool (IMAT) consists of a menu driven executive system coupled with a relational database which links commercial structures, structural dynamics and control codes. The IMAT graphics system, a key element of the software, provides a common interface for storing, retrieving, and displaying graphical information. The IMAT Graphics Manual shows users of commercial analysis codes (MATRIXx, MSC/NASTRAN and I-DEAS) how to use the IMAT graphics system to obtain high quality graphical output using familiar plotting procedures. The manual explains the key features of the IMAT graphics system, illustrates their use with simple step-by-step examples, and provides a reference for users who wish to take advantage of the flexibility of the software to customize their own applications.

Stockwell, Alan E.↗

Control-structures Interaction Test of the LACE Satellite

It is clear that additional experience and validation of Control Structures Interaction (CSI) techniques are needed in controlling the structural dynamics of flexible spacecraft. It is also clear that the effects of the space environment such as weightlessness dictate that this be done in space. Unfortunately, orbital tests are difficult to achieve because of the high cost of the test article, the launch into orbit, the instrumentation, and communication systems. The Low-power Atmospheric Compensation Experiment (LACE) Satellite has provided an opportunity to achieve a CSI test in space for very little cost. First, the CSI test rode piggy-back and did not interfere with the primary objective of LACE. Second, the novel technique of using ground based measurements of vibration of the orbiting satellite was employed. The LACE has a heavy central body to which is attached booms with lengths as long as 150 feet. The ground measurements were obtained using laser Doppler radar at the MIT Lincoln Laboratory Firepond Facility. The initial tests demonstrated the accuracy of the vibration measurements and obtained structural responses for enhancing the accuracy of the mathematical model of the structural dynamics. Germanium corner-cube retroreflectors attached to the central body and a boom deployed to 18 feet ensured a high strength return signal. Subsequent tests demonstrated the ability of an open-loop damper to attenuate the vibrations of the orbiting satellite. The LACE test results are important in contributing to the validation of a CSI technique, and demonstrating a novel ground measurement technique for orbital tests that is accurate but which has very low cost.

Taylor, Lawrence W., Jr.↗

Active damping in a flexible manipulator

Viewgraphs on active damping in a flexible manipulator are presented. Topics covered include: Shuttle Remote Manipulator System (SRMS); flexible structures; vibration; modeling of a flexible manipulator dynamical structure; designing control law criterion that minimizes vibration; and candidate application of fuzzy logic control law to the problem.

Pham, Trung T.↗

Dynamics and Control of Orbiting Space Structures NASA Advanced Design Program (ADP)

The report summarizes the advanced design program in the mechanical engineering department at Vanderbilt University for the academic years 1994-1995 and 1995-1996. Approximately 100 students participated in the two years of the subject grant funding. The NASA-oriented design projects that were selected included lightweight hydrogen propellant tank for the reusable launch vehicle, a thermal barrier coating test facility, a piezoelectric motor for space antenna control, and a lightweight satellite for automated materials processing. The NASA supported advanced design program (ADP) has been a success and a number of graduates are working in aerospace and are doing design.

Cruse, T. A.↗

Space Solar Power Technical Interchange Meeting 2: SSP TIM 2

The 2nd Space Solar Power Technical Interchange Meeting (SSP TIM 2) was conducted September 21st through 24th with the first part consisting of a Plenary session. The summary results of this Plenary session are contained in part one of this report. The attendees were then organized into Working Breakout Sessions and Integrated Product Team (IPT) Sessions for the purpose of conducting in-depth discussions in specific topic areas and developing a consensus as to appropriate study plans and actions to be taken. The Second part covers the Plenary Summary Session, which contains the summary results of the Working Breakout Sessions and IPT Sessions. The appendix contains the list of attendees. The ob'jective was to provide an update for the study teams and develop plans for subsequent study activities. This SSP TIM 2 was initiated and the results reported electronically over the Internet. The International Space Station (ISS) could provide the following opportunities for conducting research and technology (R&T) which are applicable to SSP: (1) Automation and Robotics, (2) Advanced Power Generation, (3) Advanced Power Management & Distribution (PMAD), (4) Communications Systems and Networks, (5) Energy Storage, (6) In Space Propulsion (ISP), (7) Structural Dynamics and Control, and Assembly and (8) Wireless Power Transmission.

Sanders, Jim↗

The International Space Station as a microgravity research platform

The International Space Station will provide a "World Class" environment for microgravity research. Ensuring this environment requires care in all aspects of its design. These aspects include consideration of the acceleration at near-orbit-tune-periods, such as gravity gradients and station drag, as well as controlling station structural dynamic modes, mechanical disturbances, and crew disturbances. Station designers must also ensure that the required acceleration environment is provided for long duration. The microgravity requirements placed on ISS will be reviewed, along with major considerations for achieving such an environment. Further, a description of the Space Station program strategy and implementation for meeting those requirements will be discussed. c2002 Published by Elsevier Science Ltd.

Spacecraft/instrumentation/standards↗

Heliogyro Solar Sail Research at NASA

The recent successful flight of the JAXA IKAROS solar sail has renewed interest within NASA in spinning solar sail concepts for high-performance solar sailing. The heliogyro solar sail, in particular, is being re-examined as a potential game-changing architecture for future solar sailing missions. In this paper, we present an overview of ongoing heliogyro technology development and feasibility assessment activities within NASA. In particular, a small-scale heliogyro solar sail technology demonstration concept will be described. We will also discuss ongoing analytical and experimental heliogyro structural dynamics and controls investigations and provide an outline of future heliogyro development work directed toward enabling a low cost heliogyro technology demonstration mission ca. 2020.

Wilkie, W. Keats↗

NASA Marshall Space Flight Center Controls Systems Design and Analysis Branch

Marshall Space Flight Center maintains a critical national capability in the analysis of launch vehicle flight dynamics and flight certification of GN&C algorithms. MSFC analysts are domain experts in the areas of flexible-body dynamics and control-structure interaction, thrust vector control, sloshing propellant dynamics, and advanced statistical methods. Marshall's modeling and simulation expertise has supported manned spaceflight for over 50 years. Marshall's unparalleled capability in launch vehicle guidance, navigation, and control technology stems from its rich heritage in developing, integrating, and testing launch vehicle GN&C systems dating to the early Mercury‐Redstone and Saturn vehicles. The Marshall team is continuously developing novel methods for design, including advanced techniques for large‐scale optimization and analysis.

Gilligan, Eric↗

Investigation of Phase Transition-Based Tethered Systems for Small Body Sample Capture

This paper summarizes the modeling, simulation, and testing work related to the development of technology to investigate the potential that shape memory actuation has to provide mechanically simple and affordable solutions for delivering assets to a surface and for sample capture and possible return to Earth. We investigate the structural dynamics and controllability aspects of an adaptive beam carrying an end-effector which, by changing equilibrium phases is able to actively decouple the end-effector dynamics from the spacecraft dynamics during the surface contact phase. Asset delivery and sample capture and return are at the heart of several emerging potential missions to small bodies, such as asteroids and comets, and to the surface of large bodies, such as Titan.

deployable systems↗