Documents concerning planetary quarantine are listed. Author and permuted title indexes are included for 282 citations.
Topics: NASA Technical Reports Server (NTRS), PLANETARY QUARANTINE, BACTERIA, CONTAMINANTS, INDEXES...
There are no author-identified significiant results in this report.
Topics: NASA Technical Reports Server (NTRS), KANSAS, LAKES, RESERVOIRS, WATER QUALITY, WATER RESOURCES,...
There are no author-identified significant results in this report.
Topics: NASA Technical Reports Server (NTRS), GEOLOGICAL SURVEYS, MAPPING, NEW MEXICO, PHOTOINTERPRETATION,...
Sonic-boom pressure signatures recorded during the ascent phase of Apollo 17 are presented. The measurements were obtained onboard six U.S. Navy ships positioned along the ground track of the spacecraft vehicle in the area of expected focus resulting from the flight path and acceleration of the vehicle. Tracings of the measured signatures are presented along with values of the maximum positive overpressure, positive impulse, signature duration, and bowshock rise time. Also included are brief...
Topics: NASA Technical Reports Server (NTRS), APOLLO 17 FLIGHT, ASCENT TRAJECTORIES, BOW WAVES,...
The design criteria and test options for aerospace structural reliability were investigated. A decision methodology was developed for selecting a combination of structural tests and structural design factors. The decision method involves the use of Bayesian statistics and statistical decision theory. Procedures are discussed for obtaining and updating data-based probabilistic strength distributions for aerospace structures when test information is available and for obtaining subjective...
Topics: NASA Technical Reports Server (NTRS), AIRFRAMES, RELIABILITY ENGINEERING, SERVICE LIFE, STRUCTURAL...
A glass suitable for glass-to-metal seals that has a resistance to attack by moisture and a high coefficient of linear thermal expansion is introduced. Linear expansion covers the range from 12 to 14 x 10 to the minus 6 C between room temperature and 500 C. The glass is essentially composed of, by molar percent, about 9% of K2O, about 10% of Na2O, about 70% of SiO2, about 6% Al2O3, and about 5% of MgO.
Topics: NASA Technical Reports Server (NTRS), GLASS, METALS, SEALS (STOPPERS), THERMAL EXPANSION,...
For abstract, see N75-18672.
Topics: NASA Technical Reports Server (NTRS), LANDSAT SATELLITES, SATELLITE ORBITS, SATELLITE-BORNE...
A solid, half-scale model of a 50.8-cm (20-in) research turbine designed for a high temperature core engine application was investigated over a range of speeds and pressure ratios. The results of this test are presented. The effect of rotor blade twist was also investigated. At the design equivalent speed and specific work output, the total efficiency of the turbine with untwisted rotor blades was 87.1 percent; at the same pressure ratio the efficiency of the turbine with twisted rotor blades...
Topics: NASA Technical Reports Server (NTRS), AERODYNAMIC CHARACTERISTICS, PERFORMANCE TESTS, SCALE MODELS,...
Design and performance of a highly efficient experimental 200-watt traveling wave tube for space communications are described. The tube uses a coupled cavity slow wave structure with periodic permanent magnet focusing. A two-step velocity taper is incorporated in the slow wave structure for velocity resynchronization with the modulated beam. The spent beam is reconditioned in a refocusing section before it is collected in a novel multistage depressed collector. The collector is radiation cooled...
Topics: NASA Technical Reports Server (NTRS), SPACE COMMUNICATION, TRAVELING WAVE TUBES, ELECTRON GUNS,...
The phenomenon of energy dissipation in spinning spacecraft is discussed with particular reference to its dependence on spacecraft inertia properties. Specific dissipation mechanisms are identified. The effect of external environmental factors on spin stability is also discussed. Generalized curves are presented relating system stability to the principal inertia ratio for various forms of energy dissipation. Dual-spin systems and the effect of lateral inertia asymmetry are also reviewed.
Topics: NASA Technical Reports Server (NTRS), ATTITUDE STABILITY, DUAL SPIN SPACECRAFT, FLEXIBLE BODIES,...
Transonic flutter and buffet results obtained from wind-tunnel tests of a low aspect ratio semispan wing model are presented. The tests were conducted to investigate potential transonic aeroelastic problems of vehicles having subsonic airfoil sections. The model employed NACA 00XX-64 airfoil sections in the streamwise direction and had a 14 deg leading edge sweep angle. Aspect ratio, and average thickness were 4.0, 0.35, and 8 percent, respectively. The model was tested at Mach numbers from 0.6...
Topics: NASA Technical Reports Server (NTRS), AEROELASTICITY, AIRFOILS, ASPECT RATIO, FLUTTER ANALYSIS,...
A program is discussed which develops a concept for measuring the electromagnetic environment on earth with equipment on board an orbiting space shuttle. Earlier work on spaceborne measuring experiments is reviewed, and emissions to be expected are estimated using, in part, previously gathered data. General relations among system parameters are presented, followed by a proposal on spatial and frequency scanning concepts. The methods proposed include a nadir looking measurement with small...
Topics: NASA Technical Reports Server (NTRS), ELECTROMAGNETIC FIELDS, RADIO FREQUENCY INTERFERENCE, SPACE...
Recent measurements of the inherent short-term stability of quartz crystal resonators are presented. These measurements show that quartz resonators are much more stable for times less than 1s than the best available commercial quartz oscillators. A simple model appears to explain the noise mechanism in crystal controlled oscillators and points the way to design changes which should permit more than 2 orders of magnitude improvement in their short-term stability. Calculations show that a...
Topics: NASA Technical Reports Server (NTRS), CRYSTAL OSCILLATORS, FREQUENCY STABILITY, QUARTZ CRYSTALS,...
A description is given of NAVSTAR and the conception validation program for the system. System compatibility and performance projections are discussed.
Topics: NASA Technical Reports Server (NTRS), GLOBAL TRACKING NETWORK, NAVSTAR SATELLITES, RESEARCH AND...
A flight-test program was conducted to determine the effect of advanced flight control systems and displays on the handling qualities of a light twin-engined airplane. A flight-director display and an attitude-command control system, used separately and in combination, transformed a vehicle with poor handling qualities during ILS approaches in turbulent air into a vehicle with good handling qualities. The attitude-command control system also improved the ride qualities of the airplane. A...
Topics: NASA Technical Reports Server (NTRS), AIRCRAFT PERFORMANCE, DISPLAY DEVICES, FLIGHT CONTROL, FLIGHT...
Conclusions of the team of specialists can be generalized as: (1) Brazing and welding of metal structures in an orbital near zero gravity condition are quite feasible. (2) Design of joints for fabrication in zero gravity will place less emphasis on the tolerances and proximity of the adjacent structures than on the quantity of liquid metal available. (3) Brazing of metallic joints has many advantages over electron beam welding for practical reasons: simplicity, launch weight, development costs,...
Topics: NASA Technical Reports Server (NTRS), ADHESION, COHESION, SPACE MANUFACTURING, WEIGHTLESSNESS,...
The results of testing an on-line quadrupole gas analyzer system are reported. Gas samples were drawn from the exhaust of a hydrogen-oxygen-nitrogen rocket which simulated the flow composition and dynamics at the combustor exit of a supersonic combustion ramjet engine. System response time of less than 50 milliseconds was demonstrated, with analytical accuracy estimated to be + or - 5 percent. For more complex chemical systems with interfering atom patterns, analysis would be more difficult. A...
Topics: NASA Technical Reports Server (NTRS), COMBUSTION PRODUCTS, EXHAUST GASES, GAS ANALYSIS, HYDROGEN...
The planetary observations presented are divided into three parts: (1) infrared photometry at all wavelengths accessible from the ground; (2) high resolution infrared mapping of Jupiter with special emphasis at 5 microns; and (3) extensive infrared observations of Comet Kohoutek. Results are briefly summarized.
Topics: NASA Technical Reports Server (NTRS), INFRARED PHOTOGRAPHY, PLANETS, SPACE EXPLORATION, KOHOUTEK...
A model that will explain the effect of gravity on liquid phase sintering was developed. Wetting characteristics and density segregation which are the two important phenomena in liquid phase sintering are considered in the model development. Experiments were conducted on some selected material combinations to study the gravity effects on liquid phase sintering, and to verify the validity of the model. It is concluded that: (1) The surface tension forces acting on solid particles in a one-g...
Topics: NASA Technical Reports Server (NTRS), GRAVITATIONAL EFFECTS, LIQUID PHASES, SPACE MANUFACTURING,...
Three case studies are presented involving data from an acoustic radar. The first two cases examine data collected during the passage of a mesoscale cold-air intrusion, probably thunderstorm outflow, and a synoptic-scale cold front. In these studies the radar data are compared to conventional meteorological data obtained from the WKY tower facility for the purpose of radar data interpretation. It is shown that the acoustic radar echoes reveal the boundary between warm and cold air and other...
Topics: NASA Technical Reports Server (NTRS), ACOUSTICS, BOUNDARY LAYERS, RADAR, REMOTE SENSORS, LOWER...
An analysis of the hydrogen-nitrogen-oxygen reaction systems in the lower stratosphere as they are initially perturbed by individual aircraft engine exhaust plumes was conducted in order to determine whether any significant chemical reactions occur, either among exhaust chemical species, or between these species and the environmental ozone, while the exhaust products are confined to intact plume segments at relatively high concentrations. The joint effects of diffusive mixing and chemical...
Topics: NASA Technical Reports Server (NTRS), AIR POLLUTION, ATMOSPHERIC DIFFUSION, CHEMICAL REACTIONS,...
The research to design, fabricate, test, and deliver a pressure vessel for the main component in an improved high-performance firefighter's breathing system is reported. The principal physical and performance characteristics of the vessel which were required are: (1) maximum weight of 9.0 lb; (2) maximum operating pressure of 4500 psig (charge pressure of 4000 psig); (3) minimum contained volume of 280 in. 3; (4) proof pressure of 6750 psig; (5) minimum burst pressure of 9000 psig following...
Topics: NASA Technical Reports Server (NTRS), BREATHING APPARATUS, COMPRESSED AIR, FIRE FIGHTING, PRESSURE...
A green line intensity variation is associated with the interplanetary and photospheric magnetic sector structure. This effect depends on the solar cycle and occurs with the same amplitude in the latitude range 60 deg N - 60 deg S. Extended longitudinal coronal structures are suggested, which indicate the existence of closed magnetic field lines over the neutral line, separating adjacent regions of opposite polarities on the photospheric surface.
Topics: NASA Technical Reports Server (NTRS), INTERPLANETARY MAGNETIC FIELDS, SOLAR CORONA, PHOTOSPHERE,...
Investigations are conducted into the optical properties of the glass and Kapton substrate materials, and three variables were chosen: deposition rate, sputter gas pressure, and film contamination time. Substrate tests have shown that fabrication of an dielectric broadband reflector would require an extremely complex and expensive filter design.
Topics: NASA Technical Reports Server (NTRS), CRYOGENIC COMPUTER STORAGE, KAPTON (TRADEMARK), OPTICAL...
Method helps determine branch current in parallel-series network in relation to total input current by inspection. Method is particularly useful for circuits with many elements when branch elements are described as admittances. If element values are variables, then these values may be expressed as admittances to find currents readily in desired branches.
Topics: NASA Technical Reports Server (NTRS), ANALYSIS (MATHEMATICS), CIRCUITS, CURRENT DISTRIBUTION,...
The development of a harness to hold the transmitter is discussed along with satellite systems for monitoring the flight paths of the birds, and incorporating biological information into the tracking signal.
Topics: NASA Technical Reports Server (NTRS), ARTIFICIAL SATELLITES, BIRDS, TRACKING (POSITION), FLIGHT...
Method demonstrates inexpensive, safe, and foolproof concept for solid propellant rocket motors, using simple handpump to deliver air. Flueric ignition was accomplished using system without stored energy and with complete absence of electrical energy and wiring.
Topics: NASA Technical Reports Server (NTRS), COMPRESSED AIR, FLUERICS, IGNITION SYSTEMS, PNEUMATIC...
A fixed-base visual simulation study has been conducted to evaluate the use of decoupled controls as a means for reducing pilot workload during approach and landing of an externally blown jet-flap short take-off and landing (STOL) transport. All six rigid-body degrees of freedom were employed with the aerodynamic characteristics based on wind-tunnel data. The primary piloting task was to use a flight director to capture and maintain a two-segment glide slope, with a closed-circuit television...
Topics: NASA Technical Reports Server (NTRS), AIRCRAFT LANDING, FLIGHT CONTROL, FLIGHT SIMULATION, SHORT...
The use of high strength and modulus of advanced filamentary composites to reduce the structural weight of aerospace vehicles was investigated. Application of the technology to space shuttle components was the primary consideration. The mechanical properties for the boron/epoxy, graphite/epoxy, and polyimide data are presented. Structural testing of two compression panel components was conducted in a simulated space shuttle thermal environment. Results of the tests are analyzed.
Topics: NASA Technical Reports Server (NTRS), COMPOSITE STRUCTURES, REINFORCED PLASTICS, REINFORCING...
A series of four nickel-based alloys containing 10 percent and 20 percent chromium in combination with 2 percent and 5 percent aluminum were fretted in dry air at temperatures to 816 C. At all temperatures, the alloys showed far less fretting wear than did high-purity nickel. This was attributed to the formation of protective oxide films on the alloys, the result of the selective oxidation of the alloy constituents. Increasing the aluminum concentration reduced fretting wear at all...
Topics: NASA Technical Reports Server (NTRS), ALUMINUM ALLOYS, CHROMIUM ALLOYS, FRETTING, HIGH TEMPERATURE...
Documentation of the NBODY trajectory optimization program is presented in the form of a mathematical development plus a user's manual. Optimal multistage-launch ascent trajectories may be determined by variational thrust steering during the upper phase. Optimal low-thrust interplanetary spacecraft trajectories may also be calculated with solar power or constant power, all-propulsion or embedded coast arcs, fixed or optimal thrust angles, and a variety of terminal end conditions. A hybrid...
Topics: NASA Technical Reports Server (NTRS), COMPUTER PROGRAMS, TRAJECTORY OPTIMIZATION, ASCENT...
Using a wave function including the 1s-2s-2p eigenstates of hydrogen and the 1s ground state of positronium, we have calculated the position and width of the lowest Feshbach resonance in the e(+)-H system, which lies between the positronium rearrangement threshold and the n=2 hydrogen threshold. The method differs from the usual close-coupling method, resembling in its formulation the projection operator technique, although orthogonality of closed-channel and open-channel functions is not...
Topics: NASA Technical Reports Server (NTRS), HYDROGEN ATOMS, POSITRONS, RESONANCE SCATTERING,...
Tests were conducted in wind tunnels during April and May 1973, on a 0.030-scale replica of the Space Shuttle Vehicle Configuration 2A. Aerodynamic loads data were obtained at Mach numbers from 0.6 to 3.5. The investigation included tests on the integrated (launch) configuration and the isolated orbiter (entry configuration). The integrated vehicle was tested at angles of attack and sideslip from -8 degrees to +8 degrees. The isolated orbiter was tested at angles of attack from -15 degrees to...
Topics: NASA Technical Reports Server (NTRS), AERODYNAMIC LOADS, PRESSURE MEASUREMENT, SPACE SHUTTLE ASCENT...
A low-speed investigation has been made on a highly-swept wing model having a thickened leading edge to determine the effect of inboard trailing-edge flaps on the characteristics of the model in pitch and sideslip. The tests were made at a Mach number of 0.227 which corresponds to a Reynolds number of about 5.53 million based on the reference chord. The results showed that deflection of the trailing-edge flaps decreased the roll due to sideslip by about 20 percent at a landing lift coefficient...
Topics: NASA Technical Reports Server (NTRS), ARROW WINGS, LATERAL STABILITY, LONGITUDINAL STABILITY,...
A detailed study of the charge composition of primary cosmic radiation for about 5000 charged nuclei from neon to iron with energies greater than 1.16 GeV/nucleon is presented. Values are obtained after corrections were made for detector dependences, atmospheric attenuation, and solar modulation. New values of 38.5, 32.4, 23.7, and 16.8 g/sq cm for the attenuation mean free paths in air for the same charge groups are presented.
Topics: NASA Technical Reports Server (NTRS), CHARGED PARTICLES, PRIMARY COSMIC RAYS, ATMOSPHERIC...
During the three manned Skylab missions, the Center for Short-Lived Phenomena (CSLP) reported a total of 39 significant events to the Johnson Space Center (JSC) as part of the Skylab Short-Lived Event Alert Program. The telegraphed daily status reports included the names and locations of the events, the track number and revolution number during which the event could be observed, the time (GMT) to within plus or minus 2 sec when Skylab was closest to the event area, and the light condition...
Topics: NASA Technical Reports Server (NTRS), REMOTE SENSORS, SPACEBORNE PHOTOGRAPHY, EARTH MOVEMENTS,...
There are no author-identified significant results in this report.
Topics: NASA Technical Reports Server (NTRS), GEORGIA, LAND USE, MINERAL DEPOSITS, MULTISPECTRAL...
An evaluation of the thermal and mechanical properties was performed on a molded low-density elastomeric ablation material designated as Material B. Both the virgin and charred states were examined to provide meaningful inputs to the design of a thermal protection system. Chars representative of the flight chars formed during ablation were prepared in a laboratory furnace from 600 K to 1700 K and properties of effective thermal conductivity, heat capacity, porosity and permeability were...
Topics: NASA Technical Reports Server (NTRS), ABLATIVE MATERIALS, COMPOSITE MATERIALS, ELASTOMERS, GLASS...
This special bibliography lists 417 reports, articles, and other documents introduced into the NASA scientific and technical information system in December 1973.
Topics: NASA Technical Reports Server (NTRS), AERODYNAMICS, AERONAUTICAL ENGINEERING, AERONAUTICS, AIRCRAFT...
The three dimensional equations of motion for a cable connected space station--counterweight system are developed using a Lagrangian formulation. The system model employed allows for cable and end body damping and restoring effects. The equations are then linearized about the equilibrium motion and nondimensionalized. To first degree, the out-of-plane equations uncouple from the inplane equations. Therefore, the characteristic polynomials for the in-plane and out-of-plane equations are...
Topics: NASA Technical Reports Server (NTRS), CABLES (ROPES), SPACE STATIONS, SPACECRAFT CONFIGURATIONS,...
Technical papers presented at the symposium by selected representatives from industry, universities, and various Air Force, Navy, and NASA installations are given. The topics covered include the newest developments in identification techniques, the most recent flight-test experience, and the projected potential for the near future.
Topics: NASA Technical Reports Server (NTRS), AIRCRAFT CONTROL, CONFERENCES, FLIGHT TESTS, MAXIMUM...
A finite-difference program is described for calculating the viscous compressible boundary layer flow over either planar or axisymmetric surfaces. The flow may be initially laminar and progress through a transitional zone to fully turbulent flow, or it may remain laminar, depending on the imposed boundary conditions, laws of viscosity, and numerical solution of the momentum and energy equations. The flow may also be forced into a turbulent flow at a chosen spot by the data input. The input may...
Topics: NASA Technical Reports Server (NTRS), BOUNDARY LAYER FLOW, BOUNDARY LAYER SEPARATION, COMPRESSIBLE...
First-cut estimates are given of the performance advantages of liquid-hydrogen-fueled, ejector wing, V/STOL aircraft designed for shipboard delivery and search-type missions. Results indicate that the use of LH2 could reduce gross weights 30 percent, empty weights 15 percent, and energy consumption 10 percent for a fixed payload and mission. If gross weight is fixed, the delivery range could be increased about 60 percent or the hover time during a search mission doubled. No analysis or...
Topics: NASA Technical Reports Server (NTRS), AIRCRAFT PERFORMANCE, HYDROGEN FUELS, LIQUID HYDROGEN, V/STOL...
Manual retrieval methods were used to complete 54 searches of interest for the General Aviation Newsletter. Subjects of search ranged from television transmission to machine tooling, Apollo moon landings, electronic equipment, and aerodynamics studies.
Topics: NASA Technical Reports Server (NTRS), AEROSPACE SCIENCES, INFORMATION RETRIEVAL, SEARCH PROFILES,...
The ASTP fluid transfer measurement experiment flight system design concept was verified by the demonstration and test of a breadboard model. In addition to the breadboard effort, a conceptual design of the corresponding flight system was generated and a full scale mockup fabricated. A preliminary CEI specification for the flight system was also prepared.
Topics: NASA Technical Reports Server (NTRS), BREADBOARD MODELS, FLUID FLOW, FLIGHT SIMULATION, URINE,...
This publication represents a relisting of the Skylab-2, PTD Handheld Photography Catalog. The purpose of this publication is to provide imagery researchers a supplement to the PTD Catalog by alphabetically sorting together all similar major and minor features. Some cross-referencing of feature names was accomplished where the authors deemed necessary; however, no attempt was made to exhaust all possible means of cross-referencing. An example of the cross-referencing which was done: Kuril...
Topics: NASA Technical Reports Server (NTRS), CATALOGS (PUBLICATIONS), SKYLAB PROGRAM, SKYLAB 2, SPACEBORNE...
For abstract, see N74-23389.
Topics: NASA Technical Reports Server (NTRS), AERODYNAMIC LOADS, SPACE SHUTTLES, WIND TUNNEL TESTS, ANGLE...
The theory, computer program, and numerical results of an investigation of an axial slot antenna on a circular cylinder are discussed. The cylinder is partially coated with a dielectric layer and the antenna radiates through a flush mounted window. The study was conducted to determine the effects of a high temperature dielectric layer on the performance of antennas mounted on a space shuttle. Mathematical models are developed to show the relationships of the parameters. Curves are developed to...
Topics: NASA Technical Reports Server (NTRS), ANTENNA RADIATION PATTERNS, ELECTROMAGNETIC RADIATION, SLOT...
A path selection system evaluation test procedure has been developed to enhance the analysis capability of an existing digital computer simulation package. The procedure investigates the obstacle avoidance ability of a path selection system on a sequence of test terrains with and without random effects. Using the standard test procedure a proposed mid-range sensor system has been evaluated and recommendations directed at improving the performance of the system have been made. In addition, the...
Topics: NASA Technical Reports Server (NTRS), COMPUTERIZED SIMULATION, MARS PROBES, TRAJECTORY ANALYSIS,...
A user's manual for a computer program which calculates real gas turbulent boundary layers with variable edge entropy on a blunt cone or flat plate at zero angle of attack is presented. An integral method is used. The method includes the effect of real gas in thermodynamic equilibrium and variable edge entropy. A modified Crocco enthalpy velocity relationship is used for the enthalpy profiles and an empirical correlation of the N-power law profile is used for the velocity profile. The...
Topics: NASA Technical Reports Server (NTRS), COMPUTER PROGRAMS, GAS FLOW, THERMODYNAMIC EQUILIBRIUM,...
