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Results for “disconnection”

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 181 records · Page 10

All sources NASA NTRS DOE OSTI

NASA NTRS1973

Attitude sensor

A device for controlling the attitude of a spacecraft is described. The device consists of two light sensors on a spacecraft that are mounted beneath a baffle which divides the light from a light source such as the sun or a star. The divided light reflects off of two reflective surfaces onto the two light sensors. When the spacecraft assumes its normal attitude, the baffle divides the light source into two equal parts, causing the two light sensors to produce equal outputs. When the light is equally detected, the stabilizing system is disconnected. Deviations from the normal attitude cause unequal distribution of the light source and energize the stabilizing system.

Newcomb, A. L., Jr.↗

NASA NTRS1974

Fabrication technology: A compilation

A compilation is presented which supplies technical information on the assembly of diverse components into functional assemblies and subassemblies, as well as information on several fasteners and fastening techniques that join components, subassemblies, and complete assemblies to achieve a functional unit. Quick-disconnect fasteners are described, along with several devices and methods for attaching thermal insulators, and for joining and separating objects in the absence of gravity.

Source record↗

NASA NTRS1975

Ice pack heat sink subsystem, phase 2

The report describes the design, development, fabrication, and test at one gravity of a prototype ice pack heat sink subsystem to be used eventually for astronaut cooling during manned space missions; the investigation of thermal storage material with the objective of uncovering materials with heats of fusion and/or solution in the range of 300 Btu/lb (700 kilojoules/kilogram); and the planned procedure for implementing an ice pack heat sink subsystem flight experiment. In normal use, excess heat in the liquid cooling garment (LCG) coolant is transferred to a reusable/regenerable ice pack heat sink. For emergency operation, or for extension of extravehicular activity mission time after all the ice has melted, water from the ice pack is boiled to vacuum, thereby continuing to remove heat from the LCG coolant. This subsystem incorporates a quick disconnect thermal interface between the ice pack heat sink and the subsystem heat exchanger.

Roebelen, G. J., Jr.↗

NASA NTRS1975

Electrostatic measurement system

A system for and method of contact-electrifying a dielectric to determine its electrostatic properties is described. The dielectric is placed in contact with a contact plate means, and connected to a voltage source means to charge the contact plate and to contact-electrify the dielectric. The contact plate means is disconnected from the voltage source and a charge sensor means monitors the rate of decay of the charge on the dielectric. If a conductive path from the contact plate to ground is desired, a lead may be connected between the conductor and ground. Automatic timing and charge monitoring are preferred for maximum accuracy, especially where dielectrics treated with antistatic agents are tested.

Johnston, J. E.↗

NASA NTRS1977

Paddle-pin alinement test

Segmented insulated test bar speeds up patch distributor paddle-pin test. Device eliminates need to disconnect cables or remove distributor. Printed circuit cable and connector reduces weight on bar, adding to tester portability.

Gilliam, D. M.↗

NASA NTRS1975

Fusible heat sink for EVA thermal control

The preliminary design and analysis of a heat sink system utilizing a phase change slurry material to be used eventually for astronaut cooling during manned space missions is described. During normal use, excess heat in the liquid cooling garment coolant is transferred to a reusable/regenerable fusible heat sink. Recharge is accomplished by disconnecting the heat sink from the liquid cooling garment and placing it in an on board freezer for simultaneous slurry refreeze and power supply electrical rechange.

Roebelen, G. J., Jr.↗

NASA NTRS1975

Development of a bone-fixation prosthetic attachment

An artificial limb attached directly to the bone by a quick-disconnect coupling was tested in-place at a California medical rehabilitation center. Its design concept and development, made possible by multiple spinoffs of aerospace technology, are discussed.

Owens, L. J.↗

NASA NTRS1976

A model for polar cap electric fields

A model is proposed relating polar cap ionospheric electric fields to the parameters of the solar wind near the orbit of the earth. The model ignores the notion of field line merging. An essential feature is the role played by velocity shear instabilities in regions of the outer magnetosphere, in which mapping of the magnetosheath electric field would produce sunward convection. The anomalous resistivity which arises from velocity shear turbulence, suffices to essentially disconnect the magnetosphere from the magnetosheath, at any place where that resistivity is large enough. The magnetosheath-magnetosphere system, as a consequence, acts as a kind of diode or rectifier for the magnetosheath electric fields. Predictions of the model are compared with several observations related to polar cap convection.

Dangelo, N.↗

NASA NTRS1975

Retrieval of the HEAO-C spacecraft with Space Shuttle

A plan has been developed to retrieve the HEAO-C spacecraft from orbit with the Space Shuttle in the early 1980s. The initial HEAO-C orbit altitude must be increased to provide additional lifetime. A simple passive stabilization mode, using gravity gradient and aerodynamic torques, is used for long-term storage. Most of the modifications required for Orbiter compatibility result from manned safety requirements and the structural mounting. There is a positive disconnect of all power before entering the Orbiter bay, and pressure vessels are monitored continuously. Structural equipment is added in the Orbiter bay to receive and stow the Observatory.

Mitchell, D. H.↗

NASA NTRS1976

A multilevel optimization of large-scale dynamic systems

A multilevel feedback control scheme is proposed for optimization of large-scale systems composed of a number of (not necessarily weakly coupled) subsystems. Local controllers are used to optimize each subsystem, ignoring the interconnections. Then, a global controller may be applied to minimize the effect of interconnections and improve the performance of the overall system. At the cost of suboptimal performance, this optimization strategy ensures invariance of suboptimality and stability of the systems under structural perturbations whereby subsystems are disconnected and again connected during operation.

Siljak, D. D.↗

NASA NTRS1976

Disjoint design spaces in the optimization of harmonically excited structures

The paper deals with a method of optimizing harmonically or dynamically excited structures which removes the frequency constraint (that specifies that the structure's first natural frequency of vibration must be greater than the excitation frequency), replaces the displacement constraint by an inequality constraint on the allowable stress and applies finite element approximations to the continuous one-dimensional structures. When the problem is posed in this manner, the feasible design space is disconnected or 'disjoint'. An attempt is made to explain this disjointness by studying the optimal design of a thin-walled cantilevered rod subjected to steady, simple harmonic torsional excitation. The finite element method is applied to the optimization of a harmonically excited structure with an arbitrary number of design variables, with the disjointness of the design space, a complicating factor.

Johnson, E. H.↗

NASA NTRS1977

Skin-implant multiwire connector

Construction of device utilizing high-purity carbon is biocompatible as well as hygienic, Design allows for easy connections and disconnections in dark, cleaning and maintenance and less snagging of clothing and other articles by device. Guides and magnetic coupling preclude need for locks, screwing, or latching.

Owens, L. J.↗

NASA NTRS1976

Electrically rechargeable REDOX flow cell

A bulk energy storage system is designed with an electrically rechargeable reduction-oxidation (REDOX) cell divided into two compartments by a membrane, each compartment containing an electrode. An anode fluid is directed through the first compartment at the same time that a cathode fluid is directed through the second compartment. Means are provided for circulating the anode and cathode fluids, and the electrodes are connected to an intermittent or non-continuous electrical source, which when operating, supplies current to a load as well as to the cell to recharge it. Ancillary circuitry is provided for disconnecting the intermittent source from the cell at prescribed times and for circulating the anode and cathode fluids according to desired parameters and conditions.

Thaller, L. H.↗

NASA NTRS1976

Percutaneous connector device

A device is reported for facilitating the passage of electrical signals from an external source through the skin of a patient to internal portions of the body such as muscles and nerves. The connector device includes a bio-compatible shell having an enlarged disk shaped portion for being implanted below the skin of the patient. The shell has a first and second electrically conductive post carried therein upon which a plug can be readily connected and disconnected. A modified form of the invention utilizes a unipolar connector that is adapted to be plugged into a shell implanted below the skin of a patient. Both of the connector devices are designed to be separated when a predetermined force is applied. This prevents excessive force from being applied to the implanted bio-compatible shell.

Parsons, W. E.↗

NASA NTRS1976

Long life testing of spare Mariner Venus '67 hardware

The faultless performance of the Mariner Venus '67 Power Conditioning Electronics (PCE) throughout six years of continuous operation in a simulated space environment is reported. Weekly functional tests supplemented by daily monitoring verified that the PCE equipment can perform to its intended functions for at least six years without apparent performance degradation. Performance throughout the test period was very stable, there are no circuit or redundancy improvements to be considered. When the equipment was examined after the test was completed, there was no evidence of any physical damage nor any difficulty in disconnecting the wiring connectors.

Silverman, S. W.↗

NASA NTRS1977

Program Documentation for Elapsed Time to Oxygen and Hydrogen Caution and Warning System for Captive/active 1 and 3 Flights

High pressure gas storage simulation runs were made to compute the elapsed time from T-O disconnect (transfer to onboard reactant) to the caution and warning pressures for the primary oxygen (O2) and hydrogen (H2) systems of Orbiter Vehicle (OV) 101. The simulation runs were made for approach and landing test flights Captive/Active 1 and Captive/Active 3.

Hurst, J. E.↗

NASA NTRS1976

A fusible heat sink concept for extravehicular activity /EVA/ thermal control

This paper describes the preliminary design and analysis of a heat sink system, utilizing a phase change slurry material, to be used for astronaut and equipment cooling during manned space missions. During normal use, excess heat in the liquid cooling garment (LCG) coolant is transferred to a regenerable fusible heat sink. Recharge is accomplished by disconnecting the heat sink from the liquid cooling garment and placing it in an onboard freezer for simultaneous slurry refreeze and power supply recharge.

Roebelen, G. J., Jr.↗

NASA NTRS1979

Automatic circuit interrupter

In technique, voice circuits connecting crew's cabin to launch station through umbilical connector disconnect automatically unused, or deadened portion of circuits immediately after vehicle is launched, eliminating possibility that unused wiring interferes with voice communications inside vehicle or need for manual cutoff switch and its associated wiring. Technique is applied to other types of electrical actuation circuits, also launch of mapped vehicles, such as balloons, submarines, test sleds, and test chambers-all requiring assistance of ground crew.

Dwinell, W. S.↗