Fabrication, spin testing and magnetic testing of a welded rotor in a 36000 RPM Lundell alternator
Inconel-steel, puddle-welded rotor spin and magnetic testing for use in 36,000 rpm Lundell alternator
Lumannick, S.↗
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Experimental performance of a 10 kW, 1200 hertz Brayton cycle alternator and controls for space power
Steady state and transient performance of Brayton cycle alternator and electronic controls for space power
Ingle, B. D.↗
Reduction of alternator apparent-power requirements and harmonic distortion caused by phase-controlled parasitic loads
Steady state analysis of phase controlled parasitic current, discussing reduction of alternator apparent power requirements and harmonic distortion
Gilbert, L. J.↗
Alternate avionics system study and phase B extension
Results of alternate avionics system studies for the space shuttle are presented that reduce the cost of vehicle avionics without incurring major off-setting costs on the ground. A comprehensive summary is provided of all configurations defined since the completion of the basic Phase B contract and a complete description of the optimized avionics baseline is given. In the new baseline, inflight redundancy management is performed onboard without ground support; utilization of off-the-shelf hardware reduces the cost figure substantially less than for the Phase B baseline. The only functional capability sacrificed in the new approach is automatic landing.
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Correlation of windage-loss data for a Lundell alternator
Viscous torque (windage) of a Lundell-shaped rotor having a major diameter of 20.3 cm (8 in.) rotating within a concentric housing was measured at speeds up to 36,000 rpm. The center cylindrical section of the housing was tested with both a smooth surface and axial slots to simulate alternator winding slots. For concentric cylinders, the range of Reynolds numbers was extended to 70,000. Three radial clearances, 1, 2, and 4 mm (0.04, 0.08, and 0.16in.), corresponding to 1, 2, and 4 percent of the rotor radius, were tested.
Kempke, E. E., Jr.↗
A study of alternative methods for reclaiming oxygen from carbon dioxide and water by a solid-electrolyte process for spacecraft applications
Two alternative technical approaches were studied for application of an electrochemical process using a solid oxide electrolyte (zirconia stabilized by yttria or scandia) to oxygen reclamation from carbon dioxide and water, for spacecraft life support systems. Among the topics considered are the advisability of proceeding to engineering prototype development and fabrication of a full scale model for the system concept, the optimum choice of method or approach to be carried into prototype development, and the technical problem areas which exist.
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Circuit performance of a parasitic-loading digital speed controller for a 400-hertz turbine-driven alternator
Parasitic speed controllers are used in space power electrical generating systems to maintain the speed of the turbine-driven alternators within specified limits. Selected subcircuits for a solid state parasitic-loading speed controller were assembled and tested. The test results as obtained to date consist of the performance evaluation of the frequency reference and the period counter subcircuits. These circuits performed as expected.
Ryan, J. P.↗
On the Poincare noninvariance of a recent alternative to the Dirac equation.
Explicit construction of the infinitesimal generators of the Poincare group, demonstrating that the algebra of commutators closes only for the case of zero mass. Hence, the so-called Stigma equation proposed by Biedenharn et al. (1971) as an alternative to the Dirac equation (1928) for spin one-half, finite mass particles is not Poincare invariant except when the leptonic mass is zero.
Madan, R. N.↗
Interferometric spectropolarimetry - Alternate experimental methods.
Three alternate methods of obtaining spectra of the intensity and state of polarization of light are proposed. The methods make use of a two-beam amplitude division interferometer using the technique of Fourier spectroscopy. They do not require the presence of polarizers in the arms of the instrument. In one method a single analyzer is used in front of the detector with three successive orientations of its transmission axis azimuth. In another method, a (linear) polarizer assuming the same set of orientations is placed in the incident beam. A third method, a hybrid of the former two methods, makes use of both a polarizer and analyzer in the locations indicated. The first method permits the determination of all four Stokes parameters of polarization, whereas the other two methods cannot yield the ellipticity parameter. All methods require the recording of three interferograms. However, two interferograms can provide the intensity and degree of polarization in any of the methods described.
Fymat, A. L.↗
A study of alternative designs for a system to concentrate carbon dioxide in a hydrogen-depolarized cell
Experimental results are presented on alternative designs for a hydrogen depolarized cell to concentrate CO2 in spacecraft atmospheric control systems. Data cover technical problems, methods for solving these problems, and the suitability of such a cell for CO2 removal and control of atmospheric humidity during the flight mode.
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Preliminary design of a mini-Brayton Compressor-Alternator-Turbine (CAT)
The preliminary design of a mini-Brayton compressor-alternator-turbine system is discussed. The program design goals are listed. The optimum system characteristics over the entire range of power output were determined by performing a wide-range parametric study. The ability to develop the required components to the degree necessary within the limitations of present technology is evaluated. The sensitivity of the system to various individual design parameters was analyzed.
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Study of Alternate Space Shuttle Concepts. Volume 2, Part 2: Concept Analysis and Definition
This is the final report of a Phase A Study of Alternate Space Shuttle Concepts by the Lockheed Missiles & Space Company (LMSC) for the National Aeronautics and Space Administration George C. Marshall Space Flight Center (MSFC). The eleven-month study, which began on 30 June 1970, is to examine the stage-and-one-half and other Space Shuttle configurations and to establish feasibility, performance, cost, and schedules for the selected concepts. This final report consists of four volumes as follows: Volume I - Executive Summary, Volume II - Concept Analysis and Definition, Volume III - Program Planning, and Volume IV - Data Cost Data. This document is Volume II, Concept Analysis and Definition.
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Study of alternate space shuttle concepts
A study of alternate space shuttle concepts was conducted to examine the stage-and-one-half concept and its potential for later conversion and use in the two stage reusable shuttle system. A study of external hydrogen tank concepts was conducted to determine the issues involved in the design and production of a low-cost expendable tank system. The major objectives of the study were to determine: (1) realistic drop tank program cost estimates, (2) estimated drop tank program cost for selected specific designs, and (3) change in program cost due to variations in design and manufacturing concepts and changes in program assumptions.
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Alternate concepts study extension. Volume 2: Part 4: Avionics
A recommended baseline system is presented along with alternate avionics systems, Mark 2 avionics, booster avionics, and a cost summary. Analyses and discussions are included on the Mark 1 orbiter avionics subsystems, electrical ground support equipment, and the computer programs. Results indicate a need to define all subsystems of the baseline system, an installation study to determine the impact on the crew station, and a study on access for maintenance.
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Alternate propellants for the space shuttle solid rocket booster motors
As part of the Shuttle Exhaust Effects Panel (SEEP) program for fiscal year 1973, a limited study was performed to determine the feasibility of minimizing the environmental impact associated with the operation of the solid rocket booster motors (SRBMs) in projected space shuttle launches. Eleven hypothetical and two existing limited-experience propellants were evaluated as possible alternates to a well-proven state-of-the-art reference propellant with respect to reducing emissions of primary concern: namely, hydrogen chloride (HCl) and aluminum oxide (Al2O3). The study showed that it would be possible to develop a new propellant to effect a considerable reduction of HCl or Al2O3 emissions. At the one extreme, a 23% reduction of HCl is possible along with a ll% reduction in Al2O3, whereas, at the other extreme, a 75% reduction of Al2O3 is possible, but with a resultant 5% increase in HCl.
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Test characteristics of a welded rotor in a 36,000-rpm Lundell alternator
Two four-pole Lundell-type rotors consisting of magnetic and nonmagnetic materials were fabricated by weld-depositing Inconel 625 between two sections of AISI 4617 steel. The rotors had a major diameter of 8.28 cm (3.26 in.). Saturation curves for load and no-load conditions with one of the rotors installed in a 1200-Hz Brayton-cycle research alternator are presented. The other identical rotor was spin-tested to a speed of 63,000 rmp, which was equal to 175 percent of the rated speed.
Lumannick, S.↗
Development of a gas pressure bonded four-pole alternator rotor
Methods were developed for fabrication of a solid four pole alternator rotor by hot isostatic pressure welding. The rotor blanks welded in this program had complex geometrical mating interfaces and were of considerable bulk, being approximately 3-1/2 inches (0.089 meters) in diameter and 14 inches (0.356 meters) long. Magnetic end pieces were machined from AlSl 4340 steel, while the non-magnetic central section was of Inconel 718. Excellent welds were produced which were shown to be responsive to post weld heat treatments which substantially improved joint strength. Prior to welding the rotors, test specimens of complex geometry were welded to demonstrate that complex surfaces with intentional mechanical misfit could be readily joined using HIP welding. This preliminary work demonstrated not only that interface compliance is achieved during welding but that welding pressure is developed in these thick sections sufficient to produce sound joints. Integral weld-heat treatment cycles were developed that permitted the attainment of magnetic properties while minimizing residual stress associated with the allotropic transformation of 4340 steel.
Lessmann, G. G.↗
Mapping of hydrothermal alternation zones and regional rock types using computer enhanced ERTS MSS images
A combination of digital computer processing and color compositing of ERTS MSS images has been used to map hydrothermal alternation zones and regional rock types in south-central Nevada. The technique is based on enhancement of subtle visible and near infrared reflectivity differences between mineralogically dissimilar rocks, especially unaltered and altered rocks. MSS spectral bands are ratioed, pixel by pixel, in the computer and subsequently stretched. These ratio values are used to produce a new black and white image which shows the subtle spectral reflectivity differences. Additional enhancement is achieved by preparing color composites of two or more stretched ratio images. The choice of MSS bands for rationing depends on the spectral reflectance properties of the rocks to be discriminated. Although this technique is in the initial stage of development and is untested in other areas, it already appears to have considerable potential for targeting mineral prospects and for regional geologic mapping.
Rowan, L. C.↗