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At least 793 records · Page 44
All sourcesNASA NTRSDOE OSTI
NASA NTRS1962

Proceedings of the Symposium on the Protection Against Radiation Hazards in Space Book 1: Radiation Environment in Space. Effects of Space Radiation on Radio Sensitive Objects. Biological Effects of Space Radiation

The realization in recent years that outer space is traversed by high-energy radiations has caused man to reevaluate the feasibility of manned or even instrumented exploration outside our atmosphere. Fortunately, it is possible to determine the nature and intensities of these radiations and to produce similar radiations on earth by means of accelerators. Thus we can learn how to attenuate them and to design capsules which afford protection against them. Of course this protection carries a weight penalty so that there is a premium on optimizing the shield design. Many groups in the United states are engaged in research to this end,and it was the purpose of this symposium to bring these groups together so that they could exchange information. To make the meeting more comprehensive, sessions on the nature of the radiations and their effects on people and things were included. However, the major part of the meeting was devoted to discussions on shielding research, comprising theoretical calculations and experiments carried out mainly with high-energy accelerators. The symposium committee feels that the aims of the symposium were met and that progress in space research program was greatly accelerated thereby.

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NASA NTRS1972

Optimization of thermal protection systems for the space vehicle. Volume 2: User's manual

The development of the computational techniques for the design optimization of thermal protection systems for the space shuttle vehicle are discussed. The resulting computer program was then used to perform initial optimization and sensitivity studies on a typical thermal protection system (TPS) to demonstrate its application to the space shuttle TPS design. The program was developed in FORTRAN IV for CDC 6400 computer, but it was subsequently converted to the FORTRAN V language to be used on the Univac 1108.

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NASA NTRS1973

Application of ERTS-1 data to the protection and management of New Jersey's coastal environment

The author has identified the following significant results. Analysis of ERTS-1 imagery and complementary aircraft overflights has led to the development of seventeen information products that are being utilized within the Department of Environmental Protection as new sources of information for coastal zone management. Problem areas of significance to the State, and in which product development has contributed to date, have been identified as: the environmental effects of offshore waste disposal, the placement of ocean outfalls, the better understanding of littoral processes for shore protection, the delineation of the coastal ecozones, and determination of the flushing characteristics of the State's estuaries. Of equal importance has been the development of a capability within the State to use and understand remote sensor-derived information.

Yunghans, R. S.↗
NASA NTRS1974

Application of ERTS-1 data to the protection and management of New Jersey's coastal environment

The author has identified the following significant results. The principal thrust of this ERTS-1 experiment is to develop quasi-operational information products from analysis of ERTS-1 imagery and collateral aerial photography and to apply these products to the practical regulation, protection, and management of New Jersey's coastal environment. Incorporated into this goal is the development of procedures for the operational use of ERTS-1 data products within New Jersey's Department of Environmental Protection. Analysis and product preparation for operational needs has centered on four major coastal resource problem areas: detection of land use changes in the coastal zone; siting of ocean outfalls; monitoring of offshore waste disposal; and calculation of recession rates along the Atlantic Shore. The relative utility and estimated monetary benefits derived from ERTS and aircraft imagery for each problem area have been determined. Of equal importance is the development to a capability within the State to use and understand remote sensor-derived information, and the application of this information to meet the requirements of current and anticipated coastal zone legislation.

Yunghans, R. S.↗
NASA NTRS1974

Overvoltage protection network

Electrical equipment to be protected from overvoltage is connected with a possible source of overvoltage via an input conductor. A fuse is connected in series with the input conductor. A spark gap is connected between the input conductor and ground for conducting the overvoltage current to ground and for blowing the fuse to open the circuit to the electrical equipment. A pulse attenuator network is provided between the spark gap and the electrical equipment to be protected for attenuating the pulse of energy passing through the fuse and spark gap prior to blowing of the fuse. The pulse attenuator network includes additional shunt spark gaps, series inductance, and a series connection of a twisted shielded pair of conductors having low-voltage insulation.

Cambra, J. M.↗
NASA NTRS1974

Potential of thin, sputtered films as erosion resistant protective coatings, part 1

The characteristics of thin, pyrolytically deposited films for protection of surfaces from oxidation and abrasion are discussed. The limitations of depositing erosion resistant films are described. Environmental tests of first stage compressor blades in a T-58 engine after coating with a thin film were conducted. Photographic examples of the effectiveness of the thin films in protecting the turbine blades are provided. Methods for operating a sputtering system and the equipment used for film deposition are defined.

Gentner, K.↗
NASA NTRS1974

Pathogenetic validation of the use of biological protective agents and early treatment in cases of radiation injury simulating radiation effects under space flight conditions

In considering a radiation safety system for space flights, the various measures to protect man against radiation include drug prophylaxis. At the present time a great deal of experimental material has been accumulated on the prevention and treatment of radiation injuries. Antiradiation effectiveness has been established for sulfur- and nitrogen-containing substances, auxins, cyanides, polynucleotides, mucopolysaccharides, lipopolysaccharides, aminosaccharides, synthetic polymers, vitamins, hormones, amino acids and other compounds which can be divided into two basic groups - biological and chemical protective agents.

Rogozkin, V. D.↗
NASA NTRS1972

Protective overcoating of films

Kodak Film Type SO-212 was emulsion overcoated with gelatin and lacquer to evaluate the feasibility of application of the coatings, any image degradation, and the relative protection offered against abrasion. Evaluated were: Eastman motion picture film lacquer Type 485, water solutions of Eastman purified Calfskin gelatin, and experimental Eastman gelatin stripping film of 4 and 6 microns. Conclusions reached were: (1) All coatings can be applied with relative ease with the only limitation being that of equipment. (2) None of the coatings degrade the processed image. (3) All of the coatings provide protection to the emulsion. These conclusions apply to any film which may be considered for overcoating.

Maas, K. A.↗
NASA NTRS1974

Application of ERTS-1 data to the protection and management of New Jersey's coastal environment

The author has identified the following significant results. Quasi-operational information products for coastal zone management have been prepared using ERTS-1 imagery and collateral aerial photography. These products were applied to the practical regulation, protection, and management of New Jersey's coastal environment. Procedures were developed for the operational use of ERTS-1 data products within New Jersey's Department of Environmental Protection. Successful analysis and product preparation for operational needs centered on four major coastal resource problem areas: (1) detection of environmental changes in coastal areas, (2) siting of ocean outfalls, (3) monitoring of offshore waste disposal, and (4) calculation of recession rates along the Atlantic Shore. The utility and monetary benefits derived from ERTS and aircraft imagery for each problem area have been determined. The NJDEP estimates the possibility of $620,000 yearly savings through the use of an operational ERTS system and a one-time savings of $2.8 million on current or planned projects if a truly operational ERTS type satellite were available.

Yunghans, R. S.↗
NASA NTRS1976

The Langley thermal protection system test facility: A description including design operating boundaries

A description of the Langley thermal protection system test facility is presented. This facility was designed to provide realistic environments and times for testing thermal protection systems proposed for use on high speed vehicles such as the space shuttle. Products from the combustion of methane-air-oxygen mixtures, having a maximum total enthalpy of 10.3 MJ/kg, are used as a test medium. Test panels with maximum dimensions of 61 cm x 91.4 cm are mounted in the side wall of the test region. Static pressures in the test region can range from .005 to .1 atm and calculated equilibrium temperatures of test panels range from 700 K to 1700 K. Test times can be as long as 1800 sec. Some experimental data obtained while using combustion products of methane-air mixtures are compared with theory, and calibration of the facility is being continued to verify calculated values of parameters which are within the design operating boundaries.

Klich, G. F.↗
NASA NTRS1975

Space shuttle program: Lightning protection criteria document

The lightning environment for space shuttle design is defined and requirements that the design must satisfy to insure protection of the vehicle system from direct and indirect effects of lightning are imposed. Specifications, criteria, and guidelines included provide a practical and logical approach to protection problems.

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NASA NTRS1976

Material development aspects of an oxidation protection system for a reinforced carbon-carbon composite

The paper describes the procedures which led to selection of a diffusion-coated siliconized oxidation-resistant reinforced carbon-carbon composite as a candidate for use in the leading edge structure of the Space Shuttle for the purpose of providing thermal protection. Materials were evaluated on the basis of oxidation-inhibitor performance, strength properties, and fabricability. Compounds of titanium, tantalum, zirconium, silicon, hafnium, aluminum, and boron were compounded with the reinforced carbon-carbon material in two different processing techniques to discover an oxidation-inhibited system which provided multicycle protection at temperatures up to 4000 F. Details of the manufacture and testing of the reinforced carbon-carbon composites are provided.

Rogers, D. C.↗
NASA NTRS1976

Arc discharge supply component protection circuitry

In a mercury-bombardment ion engine, the discharge supply is a high-current low-voltage one that maintains an arc or discharge inside the engine. In a 30-cm engine the supply provides up to 45 volts at about 13 amperes and is referenced at approximately 1100 volts above ground. Due to the engine discharge characteristics, a very slow feedback control loop is required. A high-speed current limit must be used to protect the components in the power conditioner, a pulse-width-modulated bridge inverter. A high-speed cycle-by-cycle current-limit circuit which allows the inverter to continue running in an overcurrent condition is used to protect it. The high-speed current sensing allows the inverter to be turned off each half cycle before the current in the primary of the inverter exceeds a safe level. This permits the inverter to continue to provide current into a discharge or a fault condition, until the feedback control system can actively control the current.

Ahrens, A. F.↗
NASA NTRS1977

Ceramic composite protection for turbine disc bursts

Ceramic composite turbine disc protection panels for the A300B were developed using armor technology. Analytical predictions for modifying the ballistic projectile armor system were verified by a test program conducted to qualify the rotor containment system. With only a slight change in the areal density of the armor system a more than two-fold increase in kinetic energy protection level was achieved. Thickness of the fiberglass reinforced plastic backing material was increased to achieve an optimum ratio of ceramic thickness to backing thickness for the different ballistic defeat condition.

Gardner, P. B.↗
NASA NTRS1977

Fuel system protection

The hazardous nature of most fuels and the potential for catastrophe if ignition should occur was investigated in regard to the design of adequate lightning protection for aircraft fuel systems. Typical aircraft fuel flammability characteristics and possible ways to control fuel flammability and ignition were reviewed. Guidelines for effective protection of fuel systems were delineated.

Franklin A Fisher↗
NASA NTRS1977

Structures Protection

Materials of which an aircraft is made and the methods used to hold these materials together forming the aircraft structure were studied as factors important in protecting a modern aircraft from hazardous natural environments. Since all-metal aircraft are being replaced by aircraft constructed partly of fiber reinforced plastics with desirable light weight and high strength properties but with poor electrical conductivity, the danger of lightning strikes has become more serious. Lightning effects on metal structures were reviewed and design protection was discussed. The expected lightning effects on nonmetallic materials such as fiberglass and advanced composites were also reviewed.

Franklin A Fisher↗
NASA NTRS1970

Electroplating offers embrittlement protection

Thin copper electrodeposited layer protects metal parts in environments with which they may be incompatible. Originally developed for main engine of Space Shuttle where high strength nickle alloy bellows must operate in high-pressure hydrogen, technique protects nickel and is unaffected by forming process or subsequent heat treatment and preinstallation processing.

Daniels, C. M., Jr.↗