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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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At least 811 records · Page 45

Radiation Detection Technologies

When governing bodies seek to reduce the spread and development of nuclear material and weapons, arms control and safeguards technologies play an important role in preventing proliferation within a state that has already developed a nuclear weapon. Arms control treaties work to control the development, production, stockpiling, proliferation, distribution, or the usage of a certain weapon type or delivery system. Treaty guidelines are met using combinations of monitoring, detection, and verification technologies. 1 To verify compliance, a country must determine if the activities of another country are within the limits and obligations established by the treaty. A verifiable treaty contains an interlocking web of constraints and provisions designed to deter cheating, to make cheating more complicated and more expensive, or to make its detection timelier. In the past, the U.S. has deemed treaties to be effectively verifiable if there is confidence that significant violations can be detected in time to respond and offset any threat that the violation may create for the U.S.

61 RADIATION PROTECTION AND DOSIMETRY↗

Techniques of space photography

Design requirements and constraints of photographic equipment to provide information on surface topography of Moon and Mars

Summers, R. L.↗

The requirements for a new full scale subsonic wind tunnel

Justification and requirements are presented for a large subsonic wind tunnel capable of testing full scale aircraft, rotor systems, and advanced V/STOL propulsion systems. The design considerations and constraints for such a facility are reviewed, and the trades between facility test capability and costs are discussed.

Kelly, M. W.↗

Communications systems checkout study

The results and conclusions of an engineering study of Space Station communications subsystem checkout are reported. The primary purpose of the study is to recommend specific guidelines and constraints for the design and utilization of the communications subsystem leading to a practical and effective means of onboard checkout implementation. Major study objectives are as follows: (1) identify candidate communications subsystem checkout concepts, (2) determine implementation impacts of feasible concepts, (3) evaluate practicality and effectiveness of alternative concepts, (4) propose baseline modifications to accommodate preferred concepts, and (5) recommend areas for additional investigation. In addition, study results are interpreted, where appropriate, in terms of their applicability to checkout of Shuttle-Orbiter communications subsystem.

Ginter, W. G.↗

Model atmosphere for engineering applications.

A model has been developed which can be used to determine system responses to nominal profiles of atmospheric parameters from orbital altitudes down to 25 km altitude. At the present time perturbations can be added to the model on an individual basis. However, future plans are for the inclusion of identified perturbations on a routine basis so that system sensitivities can be identified, evaluated, and minimized by design and operational constraints.

Smith, R. E.↗

Survey of current component reliability problems and methods for prevention.

The current reliability problems related to electronic components and microcircuits are presented in this paper. Specific process controls, design, materials, application constraints, destructive testing, electrical tests, and procedures for implementation are recommended to improve the reliability of selected electronic components.

Hamiter, L.↗

Display formats manual

The standards and procedures for the generation of operational display formats to be used in the Mission Control Center (MCC) display control system are presented. The required effort, forms, and fundamentals for the design, specifications, and production of display formats are identified. The principles of display design and system constraints controlling the creation of optimum operational displays for mission control are explained. The basic two types of MCC display systems for presenting information are described.

R L Runnels↗

Design of stiffened cylinders to resist axial compression.

A design procedure is presented for compressed cylindrical shells stiffened by stringers and rings. The approach is indirect and begins by considering the applied stress level as a primary design variable. A new method for the sizing and spacing of rings is outlined and illustrated. Emphasis is placed upon the achievement of a minimum weight design within practical constraints imposed by parameter values.

Rehfield, L. W.↗

AAFE man-made noise experiment project. Volume 1: Introduction experiment definition and requirements

An experiment was conducted to measure and map the man-made radio frequency emanations which exist at earth orbital altitudes. The major objectives of the program are to develop a complete conceptual experiment and developmental hardware for the collection and processing of data required to produce meaningful statistics on man-made noise level variations as functions of time, frequency, and geographic location. A wide dispersion measurement receiver mounted in a spacecraft operating in a specialized orbit is used to obtain the data. A summary of the experiment designs goals and constraints is provided. The recommended orbit for the spacecraft is defined. The characteristics of the receiver and the antennas are analyzed.

Source record↗

Precision orbit raising trajectories

A precision trajectory program has been developed to serve as a test bed for geocentric orbit raising steering laws. The steering laws to be evaluated have been developed using optimization methods employing averaging techniques. This program provides the capability of testing the steering laws in a precision simulation. The principal system models incorporated in the program are described, including the radiation environment, the solar array model, the thrusters and power processors, the geopotential, and the solar system. Steering and array orientation constraints are discussed, and the impact of these constraints on program design is considered.

Flanagan, P. F.↗

An advanced structural analysis/synthesis capability - ACCESS 2

An advanced automated design procedure for minimum-weight design of structures (ACCESS 2) is reported. Design variable linking, constraint deletion, and explicit constraint approximation are used to combine effectively finite-element and nonlinear mathematical programming techniques. The approximation-concepts approach to structural synthesis is extended to problems involving fiber composite structure, thermal effects, and natural frequency constraints in addition to the usual static stress and displacement limitations. Sample results illustrating these features are given.

Schmit, L. A.↗

Advanced atmospheric sounder and imaging radiometer /AASIR/ for STORMSAT

The principal mission of the three-axis stabilized STORMSAT spacecraft is to provide the necessary meteorological data for tracking, studying the detailed structure, and modeling mesoscale weather phenomena. In the area of mesoscale events, the following meteorological objectives are indicated: high-quality imagery, visible and infrared; wind velocity from cloud tracers (1 m/sec), atmospheric temperature profiles (1 K), and atmospheric humidity sounding. These objectives are reflected in the functional characteristics of the AASIR, which is a second generation meteorological sensor based on the Visible Infrared Spin-Scan Radiometer (VISSR) and the Atmospheric Sounder (VAS). The AASIR design and interface constraints with the STORMSAT spacecraft is discussed.

Chase, S. C.↗

An aerodynamic analysis of several hypersonic research airplane concepts from M = 0.2 to 6.0

Several conceptual hypersonic research airplanes, designed within the constraints of a B-52 launch aircraft, have been studied experimentally and analytically at Mach numbers from 0.2 to 6.0. Vehicles built to these criteria for Mach 6 cruise were shown to be feasible, if careful attention was paid to the low speed lift, drag, and high angle of attack stability to assure successful landings and transonic pitch angle maneuvers. The integrated scramjet engine drag was high at subsonic speeds and appears to be constant with Reynolds number. The variable geometry airfoil used previously to improve directional stability was shown to be equally adaptable to the improvement of longitudinal stability. The vortex lattice theory gave good subsonic predictions of lift, drag due to lift, and pitching moments. Wind tunnel tests must be relied on for the drag at zero lift, trim, static margins and lateral-directional stability. The Gentry Hypersonic Arbitrary Body Program gave good predictions of the trends of lift, drag, and pitching moments with angle of attack at Mach numbers above 3, but the level of the values were not consistently predicted. No currently available theory or program gave accurate predictions of directional stability or dihedral effects at hypersonic speeds.

Penland, J. A.↗