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Design and development of input/output processor and voter-comparator switch concept of guidance and control computer for space stations - Vol. 4
System analysis and computer requirements derivation of guidance and control computer for space station applications - Vol. 5
Computer programs for simulation of reconfigurable guidance and control system operation - Vol. 6
D-200 computer family, system error analysis, reliability derivation, and power converter design for reconfigurable guidance and control computer - Vol. 7
A trajectory-optimization process is described in which the optimum thrust equations are derived using the calculus of variations. The magnitude of the thrust is constrained within an upper and a lower bound, but the thrust direction is arbitrary. This formulation allows both the constant-thrust program and the variable-thrust program to be considered. For the constant-thrust program, certain propulsion-system parameters are optimized for maximum final vehicle mass. This theory has been used to study interplanetary missions to Venus and Mars using a power-limited propulsion system. Both one-way and round trip rendezvous trajectories are considered. The analysis employs a two-body inverse-square force-field model of three dimensions. An iterative routine used to solve the two-point boundary-value problem is described in the Appendix.
Evaluation of semi-active gravity gradient system - appendixes
The definition of the Extravehicular Activity (EVA) systems interface requirements and accomodations for effective integration of a production EVA capability into the space station are contained. A description of the EVA systems for which the space station must provide the various interfaces and accomodations are provided. The discussion and analyses of the various space station areas in which the EVA interfaces are required and/or from which implications for EVA system design requirements are derived, are included. The rationale is provided for all EVAS mechanical, fluid, electrical, communications, and data system interfaces as well as exterior and interior requirements necessary to facilitate EVA operations. Results of the studies supporting these discussions are presented in the appendix.
A convertible engine called the CEST TF34, using the variable inlet guide vane method of power change, was tested on an outdoor stand at the NASA Lewis Research Center with a waterbrake dynamometer for the shaft load. A new digital electronic system, in conjunction with a modified standard TF34 hydromechanical fuel control, kept engine operation stable and safely within limits. All planned testing was completed successfully. Steady-state performance and acoustic characteristics were reported previously and are referenced. This report presents results of transient and dynamic tests. The transient tests measured engine response to several rapid changes in thrust and torque commands at constant fan (shaft) speed. Limited results from dynamic tests using the pseudorandom binary noise technique are also presented. Performance of the waterbrake dynamometer is discussed in an appendix.
We consider the 5-mass kite family of self-energy Feynman integrals and present a systematic approach for constructing an ε-form basis, along with its differential equation pulled back onto the moduli space of two tori. Each torus is associated with one of the two distinct elliptic curves this family depends on. We demonstrate how the locations of relevant punctures, which are required to parametrize the full image of the kinematic space onto this moduli space, can be extracted from integrals over maximal cuts. A boundary value is provided such that the differential equation is systematically solved in terms of iterated integrals over g-kernels and modular forms. Then, the numerical evaluation of the master integrals is discussed, and important challenges in that regard are emphasized. In an appendix, we introduce new relations between g-kernels.
The usual derivations of the S and K matrices for two-particle reactions proceed through the Lippmann–Schwinger equation with formal definitions of the incoming and outgoing scattering states. Here we present a simpler alternative derivation that is carried out completely in the Hamiltonian representation, using a discrete basis of configurations for the scattering channels as well as the quasi-bound configurations of the combined fragments. We use matrix algebra to derive an explicit expression for the K matrix in terms of the Hamiltonian of the internal states of the compound system and the coupling between the channels and the internal states. The formula for the K matrix includes explicitly a real dispersive shift matrix to the internal Hamiltonian that is easily computed in the formalism. That expression is applied to derive the usual form of the S matrix as a sum over poles in the complex energy plane. Some extensions and limitations of the discrete-basis Hamiltonian formalism are discussed in the concluding remarks and in the Appendix.
A shake test was conducted to determine the dynamic characteristics of a rotor test apparatus on two strut systems with balance dampers in the Ames 40- by 80-ft wind tunnel. The rotor-off hub transfer function (acceleration per unit force as a function of frequency) was measured in the longitudinal and lateral directions, using a combination of broadband and discrete frequency excitation techniques. The dynamic data are summarized for the configurations tested, giving the following properties for each mode identified: the natural frequency, the hub response at resonance, the fixed system damping, the damping ratio, and the modal mass. The complete transfer functions are presented, and the detailed test results are included as an appendix.
Design principles of spaced, multiwall meteoroid protection are investigated in the light of experimental data generated during the Apollo Program. The outer wall or shield is shown to be the most important element in the meteoroid-spacecraft interaction. The condition of the debris is primarily a function of the shock pressure, the melting points of the meteoroid and the shield, and the length of the meteoroid and thickness of the shield. Spacing between the walls is effective up to approximately 100 times the length of the meteoroid. The required thickness of the second wall is shown to be proportional to the meteoroid mass, velocity, and density, and to the spacing between the walls, taken with exponents dependent upon the condition of the debris. The effects of placing additional elements (insulation or honeycomb cells) between the two walls are discussed, and the efficiency of various protective configurations is presented. An analysis of the meteoroid protection proposed for the Comet Halley probe is included as an appendix.
Summary studies are presented for the entire cloud observation archive from the NASA Global Atmospheric Sampling Program (GASP). Studies are also presented for GASP particle-concentration data gathered concurrently with the cloud observations. Cloud encounters are shown on about 15 percent of the data samples overall, but the probability of cloud encounter is shown to vary significantly with altitude, latitude, and distance from the tropopause. Several meteorological circulation features are apparent in the latitudinal distribution of cloud cover, and the cloud-encounter statistics are shown to be consistent with the classical mid-latitude cyclone model. Observations of clouds spaced more closely than 90 minutes are shown to be statistically dependent. The statistics for cloud and particle encounter are utilized to estimate the frequency of cloud encounter on long-range airline routes, and to assess the probability and extent of laminaar flow loss due to cloud or particle encounter by aircraft utilizing laminar flow control (LFC). It is shown that the probability of extended cloud encounter is too low, of itself, to make LFC impractical. This report is presented in two volumes. Volume I contains the narrative, analysis, and conclusions. Volume II contains five supporting appendixes.
The results of a survey of the soft X-ray sky in the C band (0.10-0.28keV) are reported. The observations were carried out using two independent flow proportional counters on board the SAS 3 X-ray satellite which had a total angular resolution of 2.9 deg FWHM, and a total exposure of 2.2 x 10 to the 4th per sq cm s sr. It is found that C band counting rates were generally inversely correlated with the column density of the neutral hydrogen on all angular scales down to the lowest angular resolution of the detectors. In the region 90-180 deg l and 0-10 deg b, the relation between C-band rates and the column densities of neutral hydrogen was fitted with a residual rms deviation of less than 13 percent by a two-component numerical model of the X-ray background. For the apparent attenuation column density a value of 2.7 x 10 to the 20th per sq cm was obtained. On the basis of a computer simulation of the SAS 3 data, it is shown that the observed clumping of interstellar matter was consistent with the magnitude of spatial fluctuations in the C-band map. When the background rates were subtracted from the survey map, the subsequent map showed foreground emission and absorption features with improved sensitivity and clarity. A series of computer-generated maps incorporating the SAS 3 data is given in an appendix.
A formvar replicator for installation in an aircraft pod has been designed, built, and flight tested on the NASA DC-8. The system incorporates a deicing capability (which can be pressure activated) to enable climb out through icing situations prior to deployment. The system can be operated at preselected speeds such that data can be recorded over a period of one to ten hours on 200 ft of 16mm film. A x2 speed control can be used during flight. Capability exists for detection of chemical constituents by appropriate doping of the formvar solution. An article entitled 'Measurements of ice particles in tropical cirrus anvils: importance in radiation balance' is attached as appendix A.
This report describes the development, modeling, and results of a generic pressurized water reactor power plant simulator that incorporates coupled electrical and thermal power dispatch to an industrial process located approximately one kilometer from the nuclear power plant. The simulator is a commercial PWR simulator that has been modified to include thermal power dispatch as described in past milestone reports [ , ]. The commercial PWR simulator is a generic simulator available from GSE SYSTEMS® (Sykesville, MD, USA) that is built using RELAP5-HDTM Real-Time Solution and in-house software developed by GSE Systems. This generic PWR (GPWR) simulator performs real-time simulation of the complete power plant from the reactor neutronics to the electricity generation and distribution. All primary, secondary, and auxiliary systems are modeled including all control logic in order to provide the most accurate representation of actual nuclear power plant (NPP) operation, and the simulator results have been rigorously verified by an actual NPP operating at approximately 1 GWe. This report is a continuation of worked performed in previous years, and supplemental information from previous reports is included in the appendix for reference.
This Corrective Measures Implementation (CMI) Progress Report documents: (i) activities conducted as part of supplemental assessment activities completed from June 2009 through November 2014; (ii) Engineering Evaluation (EE) Advanced Data Packages (ADPs); and (iii) recommendations for future activities related to corrective measures at the Site. Applicable meeting minutes are provided as Appendix A. The following EE ADPs for CRHE are included with this CMI Progress Report: center dot Supplemental Site Characterization ADP (Step 1 EE) (Appendix B) center dot Site Characterization ADP (Step 1 EE) for Hot Spot 1 (HS1) (Appendix C) center dot Remedial Alternatives Evaluation (Step 2 EE) ADP for HS1 (Appendix D) center dot Interim Measures Work Plan (Step 3 EE) ADP for HS1 (Appendix E) center dot Site Characterization ADP (Step 1 EE) ADP for Hot Spot 2 (HS2), High Concentration Plume (HCP), and Low Concentration Plume (LCP) (Appendix F) A summary of direct-push technology (DPT) and groundwater monitoring well sampling results are provided in Appendices G and H, respectively. The Interim Land Use Control Implementation Plan (LUCIP) is provided as Appendix I. Monitoring well completion reports, other applicable field forms, survey data, and analytical laboratory reports are provided as Appendices J through M, respectively, in the electronic copy of this document. Selected Site photographs are provided in Appendix N. The interim groundwater monitoring plan and document revision log are included as Appendices O and P, respectively. KSC Electronic Data Deliverable (KEDD) files are provided on the attached compact disk.