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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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Linear sawtooth voltage wave generator with transistor timing circuit having capacitor and zener diode feedback loops
Switching circuit with regeneratively connected transistors eliminating power consumption when not in use
Picosecond light pulse measurement by two beam overlap technique using nonlinear photoelectric effect
Reversible ring counter using cascaded single silicon controlled rectifier stages
Magnetic element position sensing device, using misaligned electromagnets
Ultrasonic wrench for applying vibratory energy to mechanical fasteners
Determining feasibility of using laser beam holography for detection and characterization of bond defects in composite material structures
Pulse generating circuit for operation at very high duty cycles and repetition rates
Vortex and coaxial flow of argon and helium plasmas heated inductively, and strong magnetic field effects on turbulent plasma mixing, for gas core reactors
Analysis of concept of spin-stabilized synchronous satellite carrying interferometer transmitting CW signals in L-band
Wind tunnel static longitudinal stability and control characteristics of cruciform delta winged missile with various horizontal canards and trailing-edge flap control between Mach 1.50 and 4.63
Spacecraft attitude control microthrustors utilizing catalytically reactive gas mixtures during pulse mode and steady state operation
Multimode slow wave planar spiral antenna design and radiation field characteristics
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An attempt to improve the performance of coherent carrier systems is described, involving optimizing the design point based upon a given practical optimizing criterion. The single-channel system is treated in detail, and a brief discussion is given on how to extend the technique to a two-channel system.
Weather satellite imagery provides the only routinely available orbital imagery depicting the high latitudes. Although resolution is low on this imagery, it is believed that a major natural feature, notably linear in expression, should be mappable on it. The transition zone from forest to tundra, the ecotone, is such a feature. Locational correlation is herein established between a linear signature on the imagery and several ground truth positions of the ecotone in Canada.
A review of the plans and preparations is presented for Skylab experiment T020, entitled Foot-Controlled Maneuvering Unit (FCMU). The FCMU is an experimental system intended to explore the use of simple astronaut maneuvering devices in the zero-gravity environment of space. This review also includes discussions of the FCMU concept and experiment hardware systems, as well as supporting experiment definition and development research studies conducted with the aid of zero-gravity simulators.
A maximum likelihood parameter estimation procedure and program were developed for the extraction of the stability and control derivatives of aircraft from flight test data. Nonlinear six-degree-of-freedom equations describing aircraft dynamics were used to derive sensitivity equations for quasilinearization. The maximum likelihood function with quasilinearization was used to derive the parameter change equations, the covariance matrices for the parameters and measurement noise, and the performance index function. The maximum likelihood estimator was mechanized into an iterative estimation procedure utilizing a real time digital computer and graphic display system. This program was developed for 8 measured state variables and 40 parameters. Test cases were conducted with simulated data for validation of the estimation procedure and program. The program was applied to a V/STOL tilt wing aircraft, a military fighter airplane, and a light single engine airplane. The particular nonlinear equations of motion, derivation of the sensitivity equations, addition of accelerations into the algorithm, operational features of the real time digital system, and test cases are described.