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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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Maximization of orbiter altitude at ALT interface airspeed, mission planning, mission analysis and software
The determination of the separation initial conditions (i.e. incidence angle) that maximize orbiter altitude at the ALT interface airspeed is considered. Optimum altitude airspeed profiles are generated for each orbiter incidence angle and tailcone configuration. Results show that the highest separation altitude does not result in the highest altitude at ALT interface airspeed. The altitude attainable at ALT interface airspeed should therefore be considered in the selection of the initial conditions (i.e. incidence angle). Without violating any known constraints, the incidence angles that maximize orbiter altitude at the ALT interface airspeeds are 7.0 deg for ALT free flight 1 and 5.5 deg for ALT free flight 6.
Proposed powered explicit guidance thrust integrals derivation/implementation. Mission planning, mission analysis and software formulation
A new exoatmospheric, powered explicit guidance (PEG) thrust integral formulation and a simple method of implementation are presented. The new thrust integral formulation is significantly simpler than that currently used in PEG. Preliminary estimates indicate a computer storage savings of 220 words, which is approximately 10 percent of the current PEG ascent program. Alternate methods of implementation that could produce even more savings are noted.
Orbiter/carrier separation for the ALT free flight no. 1 reference trajectories. Mission planning, mission analysis and software formulation
Details of the generation of the separation trajectories are discussed. The analysis culminated in definition of separation trajectories between physical separation and orbiter/carrier vortex clearance. Specifications, assumptions and analytical approach used to generate the separation trajectories are presented. Results of the analytical approach are evaluated. Conclusions and recommendations are summarized. Supporting references are listed.
Orbiter altitude at ALT interface based on ALSES (Approach and Landing Shuttle Engineering Simulation) analyses. Mission planning, mission analysis and software formulation
The details of the orbiter altitude attainable at the approach and landing tests (ALT) interface determined by the approach and landing shuttle engineering simulation (manned) were documented. The analysis culminated in the verification of the trends observed in a similar analysis performed previously on the space vehicle dynamics simulation (unmanned). Altitude variations attributable to pilot steering variability ranged between 492 ft higher to 383 ft lower. The requirement for this parametric analysis is first elaborated. The specifications, assumptions, and analytical approach used to determine the orbiter altitude at the ALT interface are then presented, followed by the results of the analytical approach and the conclusions and recommendations.
Analytic Drag Controller guidance gains evaluation. Mission planning, mission analysis and software formulation
Results of a study to optimize the guidance gains for the analytical drag control entry guidance system are presented. The guidance gains were optimized for study points chosen in all phases of entry.
Determination of cardiac size following space missions of different durations - The second manned Skylab mission
A simple method to estimate cardiac size from single frontal plane chest roentgenograms has been described. Pre- and postflight chest X-rays from Apollo 17, and Skylab 2 and 3 have been analyzed for changes in the cardiac silhouette size. The data obtained from the computed cardiothoracic areal ratios compared well with the clinical cardiothoracic diametral ratios (r = .86). Though an overall postflight decrease in cardiac size is evident, the mean difference was not statistically significant (n = 8). The individual decreases in the cardiac silhouette size postflight are thought to be due to decrements in intracardiac chamber volumes rather than in myocardial muscle mass.
Error Analysis of the Shuttle Orbital Maneuvering System P-V-T Propellant Gaging Module. Mission Planning, Mission Analysis and Software Formulation
An investigation of the shuttle orbital maneuvering system (OMS) pressure-volume-temperature (P-V-T) propellant gaging module has revealed that the gaging errors due to the combined effects of random instrumentation measurement errors, propellant loading uncertainties, and simplifying assumptions in the software are non-linear over the range of the usable propellant quantity gage (0-100%), with the largest error being at the zero point. When the OMS propellant tanks in the orbiter vehicle pods are filled to contain 100% of the maximum usable propellant, the gaging error at the zero point was determined to be 9.5% for the fuel and 9.5% for the oxidizer. When the OMS propellant tanks initially contain 50% of the maximum usable propellant, the largest gaging error is still 9.5% for the fuel and 9.5% for the oxidizer.
Space shuttle engineering and operations support. ALT separation reference trajectories for tailcone on orbiter forward and aft CG configurations. Mission planning, mission analysis and software formulation
A preflight analysis of the ALT separation reference trajectories for the tailcone on, forward, and aft cg orbiter configurations is documented. The ALT separation reference trajectories encompass the time from physical separation of the orbiter from the carrier to orbiter attainment of the maximum ALT interface airspeed. The trajectories include post separation roll maneuvers by both vehicles and are generated using the final preflight data base. The trajectories so generated satisfy all known separation design criteria and violate no known constraints. The requirement for this analysis is given along with the specifications, assumptions, and analytical approach used to generate the separation trajectories. The results of the analytical approach are evaluated, and conclusions and recommendations are summarized.
Smoothing of orbital tracking data: Mission planning, mission analysis and software formulation
The problem created by the presence of wild or outlying data points among orbital tracking data, is addressed. Consideration is given to the effects of such outliers on the orbit determination process, and methods for minimizing or even eliminating these effects are proposed. Some preliminary efforts implementing these new methods are described, and the results thus far obtained are summarized. Based on these ideas and results, recommendations are made for future investigation.
Geological and geothermal data use investigations for application explorer mission-A: Heat capacity mapping mission
The author has identified the following significant results. Analysis of local areas by point-to-point registration was achieved.
Remote manipulator system flexibility analysis program: Mission planning, mission analysis, and software formulation
A computer program is described for calculating the flexibility coefficients as arm design changes are made for the remote manipulator system. The coefficients obtained are required as input for a second program which reduces the number of payload deployment and retrieval system simulation runs required to simulate the various remote manipulator system maneuvers. The second program calculates end effector flexibility and joint flexibility terms for the torque model of each joint for any arbitrary configurations. The listing of both programs is included in the appendix.
Modifications to give HOPE/MDC 2.0 the capability to solve for or consider vent forces: Mission planning, mission analysis, and software formulation
The modifications are described as necessary to give the Houston Operations Predictor/Estimator (HOPE) program the capability to solve for or consider vent forces for orbit determination. The model implemented in solving for vent forces is described along with the integrator problems encountered. A summary derivation of the mathematical principles applicable to solve/consider methodology is provided.
Geological and geothermal data use investigations for application explorer mission-A, heat capacity mapping mission
There are no author-identified significant results in this report.
Geological and geothermal data use investigations for application explorer mission-A, heat capacity mapping mission
There are no author-identified significant results in this report.
Mission description for SAA alternate mission AS-209
Explore the source record for details and available documents.
Geological and geothermal data use investigations for application explorer mission-A, heat capacity mapping mission
There are no author-identified significant results in this report.
Application explorer mission A: Heat capacity mapping mission
There are no author-identified significant results in this report.