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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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Expandable rigidizable solar shields operational, structural and thermal performance tests conducted with spherical models for cryogenically fueled space vehicles
Gravitationally induced electric field shielding using whisker model with conducting metal surface for reducing strain dependence on altitude
Electron trapping in dielectrics, providing effective light and inexpensive spacecraft bremsstrahlung shield and lower average radiation energy at synchronous altitudes
Nuclear radiation shielding design for space base SNAP 8 reactor, discussing geometry constraints for lithium hydride and U loop layers model
Reactor shield weight optimization using FASTER-III Monte Carlo computer program for neutron and gamma ray transport
Shielded fine wire probe for total temperature rapid measurement in high speed flows, discussing construction and theoretical considerations
Viking rocket heat shield material mechanical properties, examining time-temperature superposition with continuous stress relaxation data measured in vacuum
Electromagnetic compatibility program for aerospace systems, considering EM shielding and emission
Fast neutron spectra in lead and water shielded reactor, comparing liquid scintillator measurements with discrete ordinates code calculations
Jupiter atmosphere entry probes graphite ablative heat shields performance, indicating convective and radiative blockage and graphite sublimation processes in surface heat balance
Reflecting and ablating Teflon heat shields for radiative environment of outer planets atmosphere
Method for spacing and shielding console chasis from panel is described. Small Teflon buttons are force-fitted into standard holes in console.
Shielding material containing Boron 10 and gadoliunium for neutron absorption has been developed to reduce interference from low energy neutrons in measurement of fission neutron spectrum using Li-6 fast neutron spectrometer.
A preliminary shield design for a nuclear power system utilizing a SNAP-8 reactor for space base application is presented. A representative space base configuration was selected to set the geometry constraints imposed on the design. The base utilizes two independent power packages each with a reactor operating at 600 kwt and each producing about 50 kwe. The crew compartment is located about 200 feet from each reactor and is large enough in extent to intercept a total shadow angle of 60 deg measured about the center line of each reactor.
Alternate reusable nuclear shuttle configurations were synthesized and evaluated. Particular attention was given to design factors which reduced tank exposure to direct and scattered radiation, increased payload-engine separation, and improved self-shielding by the LH2 propellant. The most attractive RNS concept in terms of cost effectiveness consists of a single conical aft bulkhead tank with a high fineness ratio. Launch is accomplished by the INT-21 with the tank positioned in the inverted attitude. The NERVA engine is delivered to orbit separately where final stage assembly and checkout are accomplished. This approach is consistent with NERVA definition criteria and required operating procedures to support an economically viable nuclear shuttle transportation program in the post-1980 period.
A practical method for computing the effectiveness of a space nuclear shield perforated by small tubing and cavities is reported. Performed calculations use solutions for a two dimensional transport code and evaluate perturbations of that solution using last flight estimates and other kernel integration techniques. In general, perturbations are viewed as a change in source strength of scattered radiation and a change in attenuation properties of the region.
An experimental evaluation of thermoluminescent dosimeters was performed in order to select high precision dosimeters for a study whose purpose is to measure gamma streaming through the coolant passages of a simulated flight type internal NERVA reactor shield. Based on this study, the CaF2 chip TLDs are the most reproducible dosimeters with reproducibility generally within a few percent, but none of the TLDs tested met the reproducibility criterion of plus or minus 2%.
Experiments have been performed to validate and to supplement the intranuclear cascade model as a method for estimating cross sections of importance to spacecraft shield design. The experimental situation is inconclusive particularly for neutron-producing reactions, but is relatively sound for reaction cross sections and for proton spectra at several hundred MeV at medium forward angles. Secondary photon contributions are imprecisely known.