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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 955 records · Page 53
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Impact gages for detecting meteoroid and other orbital debris impacts on space vehicles.

Impacts on space vehicles have been simulated using the McDonnell Douglas Aerophysics Laboratory (MDAL) Light-Gas Guns to launch particles at hypervelocity speeds into scaled space structures. Using impact gages and a triangulation technique, these impacts have been detected and accurately located. This paper describes in detail the various types of impact gages (piezoelectric PZT-5A, quartz, electret, and off-the-shelf plastics) used. This description includes gage design and experimental results for gages installed on single-walled scaled payload carriers, multiple-walled satellites and space stations, and single-walled full-scale Delta tank structures. A brief description of the triangulation technique, the impact simulation, and the data acquisition system are also included.

Mastandrea, J. R.↗
NASA NTRS1973

Binary selectable detector holdoff circuit: Design, testing, and application

A very high speed switching circuit, part of a laser radar data acquisition system, has been designed and tested. The primary function of this circuit was to provide computer controlled switching of photodiode detector preamplifier power supply voltages, typically less than plus or minus 20 volts, in approximately 10 nanoseconds. Thus, in actual use, detector and/or detector preamplifier damage can be avoided as a result of sudden extremely large values of backscattered radiation being detected, such as might be due to short range, very thin atmospheric dust layers. Switching of the power supply voltages was chosen over direct switching the photodiode detector input to the preamplifier, based on system noise considerations. Also, the circuit provides a synchronized trigger pulse output for triggering devices such as the Biomation Model 8100 100 MHz analog to digital converter.

Kadrmas, K. A.↗
NASA NTRS1974

Experimental transient vane temperatures in a cascade for gas stream temperature cycling between 922 and 1644 K (1200 and 2500 F)

Experimental transient turbine vane metal temperatures were obtained from tests conducted on air-cooled vanes installed in a four-vane cascade for a gas temperature cycled between 922 and 1644 K (1200 and 2500 F). Transient data were recorded by a high-speed data acquisition system. Temperatures at the same phase of each transient cycle were repeatable between cycles to within 11 kelvins (20 F), simulated cruise and idle steady-state readings were repeated by the cruise and idle readings taken from the ends of a transient half-cycle at low pressure to within 17 kelvins (30 F). The tests were conducted at pressure levels of 31 and 83 N-sq cm (45 and 120 psia) with coolant temperatures of 811 and 589 K (1000 and 600 F), respectively.

Gauntner, D. J.↗
NASA NTRS1974

Historics of the Space Tracking And Data Acquisition Network (STADAN), the Manned Space Flight Network (MSFN), and the NASA Communications Network (NASCOM)

The historical and technical aspects of the major networks which comprise the NASA tracking and data acquisition system are considered in a complete reference work which traces the origin and growth of STADAN, MSFN, and NASCOM up to mid-1971. The roles of these networks in both the Gemini and Apollo programs are discussed, and the separate developmental trends are identified for each network.

Corliss, W. R.↗
NASA NTRS1975

Experimental transient turbine blade temperatures in a research engine for gas stream temperatures cycling between 1067 and 1567 k

Experimental transient turbine blade temperatures were obtained from tests conducted on air-cooled blades in a research turbojet engine, cycling between cruise and idle conditions. Transient data were recorded by a high speed data acquisition system. Temperatures at the same phase of each transient cycle were repeatable between cycles to within 3.9 K (7 F). Turbine inlet pressures were repeatable between cycles to within 0.32 N/sq cm (0.47 psia). The tests were conducted at a gas stream temperature of 1567 K (2360 F) at cruise, and 1067 K (1460 F) at idle conditions. The corresponding gas stream pressures were about 26.2 and 22.4 N/sq cm (38 and 32.5 psia) respectively. The nominal coolant inlet temperature was about 811 K (1000 F).

Gauntner, D. J.↗
NASA NTRS1975

Numerical procedure for analyzing Langmuir probe data

A numerical procedure is proposed for analyzing Langmuir probe data in the presence of a two-group plasma containing both primary and Maxwellian electrons. The procedure is known as a least-squares differential-correction technique for determining the unknown coefficients of the governing equation. It is shown that for a given set of input data the results of the analysis are unique and independent of the initial estimate of electron temperature, that convergence is fastest when electron temperature is overestimated, that the results are sensitive to the region of the curve used as input and also to the voltage increment, and that plasma properties determined by the proposed numerical procedure are either consistent with those determined graphically or closer to expected values. With a suitable data acquisition system, the Fortran IV program worked out for this procedure could be used to provide real-time plasma diagnostic information for an operating ion thruster.

Beattie, J. R.↗
NASA NTRS1975

Pulse width fluctuations in mode-locked Nd:YAG lasers

The experiment consisted of a flashlamp-pumped Nd:YAG laser rod in the Brewster-Brewster configuration, passively modelocked by a thick flowing dye in contact with the high reflectivity rear mirror. A single pulse was selected by a cylindrical-ring electrode Pockel's cell, and amplified by two Nd:YAG amplifiers. Calibrated photodiodes measured the total pulse energy at the fundamental frequency and the total pulse energy at the second harmonic frequency. The signals were monitored by a digital data acquisition system and displayed on a teletype printer.

Bechtel, J. H.↗
NASA NTRS1977

Preliminary demonstration of precision DSN clock synchronization by radio interferometry

A wideband digital data acquisition system has been developed to measure the clock offsets to the 10-ns accuracy required to facilitate three-way spacecraft ranging, to monitor the hydrogen maser frequency standard rates to 1 part in 10 to the forteenth power and to potentially reduce operational costs by replacing the current DSN operational time sync system.

Hurd, W. J.↗
NASA NTRS1977

Experimental apparatus for investigation of fan aeroelastic instabilities in turbomachinery

The application, installation, and monitoring of dynamic strain gage instrumentation on the rotating fan blades for subsonic stalled flutter mode of the first fan rotor are described. The engine installation, the modifications to the engine controls to obtain off schedule operation of the fan, engine aerodynamic instrumentation, and general data acquisition systems are discussed.

Jones, W. H.↗
NASA NTRS1977

Instrumentation of sampling aircraft for measurement of launch vehicle effluents

An aircraft was selected and instrumented to measure effluents emitted from large solid propellant rockets during launch activities. The considerations involved in aircraft selection, sampling probes, and instrumentation are discussed with respect to obtaining valid airborne measurements. Discussions of the data acquisition system used, the instrument power system, and operational sampling procedures are included. Representative measurements obtained from an actual rocket launch monitoring activity are also presented.

Wornom, D. E.↗
NASA NTRS1977

In situ performance measurements of the mitre photovoltaic array

A data acquisition system was developed to provide more accurate and consistent measurement of the degradation of solar arrays. A technique was developed for in-situ measurement of photovoltaic panels of sufficient quality to permit evaluation of electrical performance over extended periods of several years.

Cherdak, A. S.↗
NASA NTRS1978

Chopper-stabilized phase detector

Phase-detector circuit for binary-tracking loops and other binary-data acquisition systems minimizes effects of drift, gain imbalance, and voltage offset in detector circuitry. Input signal passes simultaneously through two channels where it is mixed with early and late codes that are alternately switched between channels. Code switching is synchronized with polarity switching of detector output of each channel so that each channel uses each detector for half time. Net result is that dc offset errors are canceled, and effect of gain imbalance is simply change in sensitivity.

Hopkins, P. M.↗
NASA NTRS1979

Hybrid temperature-monitoring circuit

Hybrid circuit developed for use in hand-held vital signs monitor converts resistance of thermistor probe to 3 1/2 digit BCD (binary-coded-decimal) temperature readout. If used alone circuit can form 'stand alone' temperature monitor or can transmit temperature data via telemetry to data acquisition systems.

Rinard, G. A.↗
NASA NTRS1978

Evaluation of postural mechanisms under dynamic conditions

A stimulus delivery and data acquisition system for assessment of human posture was developed based on a digital computer and a translating platform. The movement of the platform acts to displace the subject's base of support while the computer tracks the corrections which are made by the subject to maintain balance. Various stimuli are used ranging from fast transients to sine waves.

Anderson, D. J.↗
NASA NTRS1978

Collation of monthly and semiannual reports covering instrumentation at the Decade 80 house in Tucson, Arizona

The Decade 80 solar house, located in Tucson, Arizona, was built to show the use of copper in home building and to demonstrate the use of solar energy to provide space heating and cooling and domestic hot water. The auxiliary energy sources are electrical resistance heating for the domestic hot water and a gas fired boiler for space heating and operation of the absorption air conditioning units. The Semi-Annual report gives an overview of the instrumentation effort with the back-up monthly reports reflecting more detail of the effort that went into the implementation of the data acquisition system.

Source record↗
NASA NTRS1979

Submicrosecond comparison of intercontinental clock synchronization by VLBI and the NTS satellite

The intercontinental clock synchronization capabilities of Very Long Baseline Interferometry (VLBI) and the Navigation Technology Satellite (NTS) were compared in May 1978 by using both methods to synchronize the cesium clocks at the NASA Deep Space Net complexes at Madrid, Spain, and Goldstone, California. The VLBI experiments used the Wideband VLBI Data Acquisition System. The Navigation Technology Satellites were used with NTS Timing Receivers developed by the Goddard Space Flight Center. The two methods agreed at about the one-half microsecond level. The VLBI system also obtained long-term stability information on the HP5061A004 cesium standards by measuring delta T/T over four 3- to 4-day intervals, obtaining stability estimates of (1 + or - 1)x10 to the -13th power for the combined timing systems.

Hurd, W. J.↗