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A fiber optic data bus, using frequency division multiplexing (FDM) is discussed. The use of FDM is motivated by the need to avoid central control of the bus operation. A major difficulty of such a data bus is introduced by the couplers. An efficient low loss access coupler with an asymmetric structure is presented, and manufacturing processes for the coupler are proposed.
The loads and aeroelasticity divisions research accomplishments are presented. The work under each branch or technical area, described in terms of highlights of accomplishments during the past year and highlights of plans for the current year as they relate to 5 year plans for each technical area. This information will be useful in program coordination with other government organizations and industry in areas of mutual interest.
Various research and technology activities at Ames Research Center's Biomedical Research Division are described. Contributions to the Space Administration's goals in the life sciences include descriptions of research in operational medicine, cardiovascular deconditioning, motion sickness, bone alterations, muscle atrophy, fluid and electrolyte changes, radiation effects and protection, behavior and performance, gravitational biology, and life sciences flight experiments.
The objectives, FY 1985 plans, approach, and FY 1985 milestones for the Structures and Dynamics Division's research programs are presented. The FY 1984 accomplishments are presented where applicable. This information is useful in program coordination with other government organizations in areas of mutual interest.
A future Space Station will require information network architectures and technologies that are evolvable, adaptive, high performing, and self-correcting and repairing. One of the conceptual network configurations involves fiber optic data buses with Wavelength Division Multiplexing (WDM). Discussion of this network concept, components being developed and results on a four-channel WDM star bus will be presented.
A new algorithm is introduced which decodes code division multiple user communication signals. The algorithm makes use of the distinctive form or pattern of each signal to separate it from the composite signal created by the multiple users. Although the algorithm is presented in terms of frequency-hopped signals, the actual transmitter modulator can use any of the existing digital modulation techniques. The algorithm is applicable to error-free codes or to codes where controlled interference is permitted. It can be used when block synchronization is assumed, and in some cases when it is not. The paper also discusses briefly some of the codes which can be used in connection with the algorithm, and relates the algorithm to past studies which use other approaches to the same problem.
The Langley Research Center Loads and Aeroelasticity Division's research accomplishments for FY85 and research plans for FY86 are presented. The rk under each branch (technical area) will be described in terms of highlights of accomplishments during the past year and highlights of plans for the current year as they relate to five year plans for each technical area. This information will be useful in program coordination with other government organizations and industry in areas of mutual interest.
Delayed division is an iterative method for solving the linear eigenvalue problem AX = lambda BX for a limited number of small eigenvalues and their corresponding eigenvectors. The distinctive feature of the method is the reduction of the problem to an approximate triangular form by systematically dropping quadratic terms in the eigenvalue lambda. The report describes the pivoting strategy in the reduction and the method for preserving symmetry in submatrices at each reduction step. Along with the approximate triangular reduction, the report extends some techniques used in the method of inverse subspace iteration. Examples are included for problems of varying complexity.
Presented are the Objectives, FY 1986 Plans, Approach, and FY 1986 Milestones for the Structures and Dynamics Division's research programs. FY 1985 Accomplishments are presented where applicable. This information is useful in program coordination with other governmental organizations in areas of mutual interest.
The research program currently being implemented by the Acoustics Division of NASA Langley Research Center is described. The scope, focus, and thrusts of the research are discussed and illustrated for each technical area by examples of recent technical accomplishments. Included is a list of publications for the last two calendar years. The organization, staff, and facilities are also briefly described.
A novel concept for a digital optical position tranducer is presented. This compact and rugged device is electrically passive and requires only a dual-fiber optical link. Wavelength division of a broad-spectrum semiconductor light source is employed to multiplex the channels of a 10-bit digital position encoder. A preliminary design was evaluated and found to have a 10-dB on-off contrast ratio and a 12-dB insertion loss.
The Loads and Aeroelasticity Division's research accomplishments for FY 86 and research plans for FY 87 are presented. The work under each Branch (technical area) is described in terms of highlights of accomplishments during the past year and highlights of plans for the current year as they relate to five year plans for each technical area. This information will be useful in program coordination with other government organizations and industry in areas of mutual interest.
This paper presents the Objectives, FY 1987 Plans, Approach, and FY 1987 Milestones for the Structures and Dynamics Division's research programs. FY 1986 Accomplishments are presented where applicable. This information is useful in program coordination with other governmental organizations in areas of mutual interest.
The presence of two about 10-km-radius satellites within a 100-km-wide gap in the Cassini division of Saturn's rings is inferred from the observation of perturbations of nearby ring material. The perturbations are detected as regular fluctuations in the optical depth profile measured during Voyager radio occultation by the rings and are used to estimate the satellite's orbits and masses. The two satellites appear to 'shepherd' a 30-km-wide ringlet within the gap.
The eight branches of the Materials Division of NASA-Lewis Research Center are described. The design and capabilities of the Microgravity Materials Science Laboratory are discussed. Consideration is given to the objectives of the ceramic branch, the advanced metallic branch, the metal science branch, and the polymer branch. Also discussed are the research and development efforts of the surface science branch, the environmental durability branch, and the analytic science branch.
The current major activites in nickel hydrogen technology being addressed at Yardney Battery Division are outlined. Five basic topics are covered: an update on life cycle testing of ManTech 50 AH NiH2 cells in the LEO regime; an overview of the Air Force/industry briefing; nickel electrode process upgrading; 4.5 inch cell development; and bipolar NiH2 battery development.
The purpose of this paper is to present the Loads and Aeroelasticity Division's research accomplishments for FY87 and research plans for FY88. The work under each Branch (technical area) is described in terms of highlights of accomplishments during the past year and highlights of plans for the current year as they relate to five year plans for each technical area. This information will be useful in program coordination with other government organizations and industry in areas of mutual interest.
A proof-of-concept (POC) aircraft is defined and the concept of interest described for each of the six aircraft developed by the Ames-Moffet Rotorcraft and Powered-Lift Flight Projects Division from 1970 through 1985; namely, the OV-10, the C-8A Augmentor Wing, the Quiet Short-Haul Research Aircraft (QSRA), the XV-15 Tilt Rotor Research Aircraft (TRRA), the Rotor Systems Research Aircraft (RSRA)-compound, and the yet-to-fly RSRA/X-Wing Aircraft. The program/project chronology and most noteworthy features of the concepts are reviewed. The paper discusses the significance of each concept and the project demonstrating it; it briefly looks at what concepts are on the horizon as potential POC research aircraft and emphasizes that no significant advanced concept in aviation technology has ever been accepted by civilian or military users without first completing a demonstration through flight testing.