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Background information on the Nimbus 5 spacecraft and experiments is presented as a basis for selecting, obtaining, and utilizing the data in research studies. The basic spacecraft system operation and the objectives of the Nimbus 5 flight are outlined, followed by a detailed discussion of each of the experiments. The format, archiving, and access to the data, and the contents and format of the Nimbus 5 Data Catalogs are described.
The data processing procedures and the computer programs were developed to predict structural responses using the Impulse Transfer Function (ITF) method. There are three major steps in the process: (1) analog-to-digital (A-D) conversion of the test data to produce Phase I digital tapes (2) processing of the Phase I digital tapes to extract ITF's and storing them in a permanent data bank, and (3) predicting structural responses to a set of applied loads. The analog to digital conversion is performed by a standard package which will be described later in terms of the contents of the resulting Phase I digital tape. Two separate computer programs have been developed to perform the digital processing.
A computer program for analyzing rocket engine performance was developed. The program is concerned with the formation, distribution, flow, and combustion of liquid sprays and combustion product gases in conventional rocket combustion chambers. The capabilities of the program to determine the combustion characteristics of the rocket engine are described. Sample data code sheets show the correct sequence and formats for variable values and include notes concerning options to bypass the input of certain data. A seperate list defines the variables and indicates their required dimensions.
A collection of computer programs and subroutines written in FORTRAN to calculate 4-body (sun-earth-moon-space) and 3-body (earth-moon-space) optimal trajectories is presented. The programs incorporate a variable step integration technique and a quadrature formula to correct single step errors. The programs provide capability to solve initial value problem, two point boundary value problem of a transfer from a given initial position to a given final position in fixed time, optimal 2-impulse transfer from an earth parking orbit of given inclination to a given final position and velocity in fixed time and optimal 3-impulse transfer from a given position to a given final position and velocity in fixed time.
The manual for the use of the computer program SYSTID under the Univac operating system is presented. The computer program is used in the simulation and evaluation of the space shuttle orbiter electric power supply. The models described in the handbook are those which were available in the original versions of SYSTID. The subjects discussed are: (1) program description, (2) input language, (3) node typing, (4) problem submission, and (5) basic and power system SYSTID libraries.
The Model is described along with data preparation, determining model parameters, initializing and optimizing parameters (calibration) selecting control options and interpreting results. Some background information is included, and appendices contain a dictionary of variables, a source program listing, and flow charts. The model was operated on an IBM System/360 Model 44, using a model 2250 keyboard/graphics terminal for interactive operation. The model can be set up and operated in a batch processing mode on any System/360 or 370 that has the memory capacity. The model requires 210K bytes of core storage, and the optimization program, OPSET (which was used previous to but not in this study), requires 240K bytes. The data band for one small watershed requires approximately 32 tracks of disk storage.
A performance-analysis computer program, that was developed explicitly to generate optimum electric propulsion trajectory data for missions of interest in the exploration of the solar system is presented. The program was primarily designed to evaluate the performance capabilities of electric propulsion systems, and in the simulation of a wide variety of interplanetary missions. A numerical integration of the two-body, three-dimensional equations of motion and the Euler-Lagrange equations was used in the program. Transversality conditions which permit the rapid generation of converged maximum-payload trajectory data, and the optimization of numerous other performance indices for which no transversality conditions exist are included. The ability to simulate constrained optimum solutions, including trajectories having specified propulsion time and constant thrust cone angle, is also in the program. The program was designed to handle multiple-target missions with various types of encounters, such as rendezvous, stopover, orbital capture, and flyby. Performance requirements for a variety of launch vehicles can be determined.
The revision of an existing digital program to analyze the stability of models mounted on a two-cable mount system used in a transonic dynamics wind tunnel is presented. The program revisions and analysis of an active feedback control system to be used for controlling the free-flying models are treated.
A description is given of the computer code for predicting viscous shock-layer flows over nonanalytic blunt bodies (Program VISLNABB) for hypersonic, low Reynolds number flows. Four specific and one general body geometries are considered. In addition to sphere-cones, cylinder wedges and geometries defined in tabular form, options for hyperboloids and paraboloids are included. Details of the theory and results are included in a separate engineering report. The program, subroutines, variables in common, and input and output data are described. Listings of the program code, output data for a sample case, and the input data for this sample case are included.
The systems cost/performance model was implemented as a digital computer program to perform initial program planning, cost/performance tradeoffs, and sensitivity analyses. The computer is described along with the operating environment in which the program was written and checked, the program specifications such as discussions of logic and computational flow, the different subsystem models involved in the design of the spacecraft, and routines involved in the nondesign area such as costing and scheduling of the design. Preliminary results for the DSCS-II design are also included.
A set of four digital computer programs is presented which can be used to investigate the effects of instrumentation errors on the accuracy of aircraft and helicopter stability-and-control derivatives identified from flight test data. The programs assume that the differential equations of motion are linear and consist of small perturbations about a quasi-steady flight condition. It is also assumed that a Newton-Raphson optimization technique is used for identifying the estimates of the parameters. Flow charts and printouts are included.
The salient conceptual features and expected evolution of the facility are discussed; the baseline design is offered as a model against which the reader can compare his needs. The overall program is discussed, supporting services and resources are described, and examples of typical payload applications are given. The general design features and configurations representing the baseline MOF developed and derived with due consideration given to applicable designs and subsystems such as those available in the Skylab, orbiter, and space lab vehicles.
The implementation of the entire systems cost/performance model as a digital computer program was studied. A discussion of the operating environment in which the program was written and checked, the program specifications such as discussions of logic and computational flow, the different subsystem models involved in the design of the spacecraft, and routines involved in the nondesign area such as costing and scheduling of the design were covered. Preliminary results for the DSCS-2 design are also included.
For abstract, see N76-25319.
Extensions developed at Langley Research Center to the VIPASA computer program are described including a procedure for simple thermal stress analysis and options for graphical display of output. Input requirements for operation of the modified program are given in detail.
Background information was given on the Nimbus 6 spacecraft and experiments as a basis for selecting, obtaining, and utilizing Nimbus 6 data in research studies. The basic spacecraft system operation and the objectives of the Nimbus 6 flight are outlined, followed by a detailed discussion of each of the experiments. The format, archiving, and access to the data are also described. Finally, the contents and format of the Nimbus 6 data catalogs are described. These catalogs will be issued periodically after the launch of Nimbus 6. They will contain representative pictorial data and daily temperature, humidity, infrared and radiometer data obtained during each period, as well as information on the collection and availability of all Nimbus 6 data.
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A guide is presented for a computer program which reads multispectral scanner data from a universal format tape and outputs an intermediate data set in card image format for use as an input data set in various data analysis development programs.