Aerospace & Aviation

Low temperature dielectric coatings for electric conductors

Radar astronomy applied to cislunar, solar, interplanetary, ionospheric, and atmospheric media

Baker-Nunn photography of Syncom II fourth stage ignition and Centaur vehicle AC-2

Radiation effects on electronic equipment of solar spacecraft - shielding requirements

Effect of ionizing radiation on series of saturated polyesters

Ionospheric absorption, gas adsorption on tungsten, ion production, and superconductivity of metals

High temperature battery development - zeolites, anode and cathode couples, and molten salts

Solubility and diffusion of ultrapure transitional elements and compounds in alkali metals

Liquid hydrogen film cooled pressure transducer for flush mounting in rocket combustion chamber

Mars atmosphere models for entry vehicle design

Spacecraft exploration of earth, atmosphere, moon, and planets

Wind tunnel tests of static lateral and directional control of twin-propeller deflected slipstream STOL aircraft

Metallurgical bonding of plasma-sprayed tungsten on hot molybdenum substrates

An analysis was performed to determine the effectiveness of solar reflectors in reducing heat transfer through the insulation of cryogenic fuel tanks located in deep space. A solar reflector, as used herein, is defined as a surface having a ratio of absorptance with respect to solar radiation to hemispherical emittance (α/ϵ) less than 1.0. This analysis considers the effect of surface coatings with α/ϵ values varying from 0.1 to 1.0 when applied to the external surfaces of bulk insulation or multifoil insulation. Results were obtained in terms of heat leak to two cryogenic propellants, liquid hydrogen and liquid oxygen, when stored at Mars, Earth, and Mercury orbital distances from the sun. The results show that, with sufficiently good insulation and low heat leaks to the propellant, α/ϵ is a reasonable criterion of merit for these coatings, but that, at larger heat leaks, consideration of ϵ (or α) is necessary. It was observed that selective finishes of α/ϵ = 0.1 on a given amount of bulk insulation material can reduce the heat leak to 40 to 55 percent of the heat leak obtained when gray finishes are considered. Or, for equivalent heat leaks, a reduction in bulk insulation material thickness of about one-half is possible with high-quality selective finishes (α/ϵ = 0.1) compared with flat reflectors. Larger benefits may be achieved from selective finishes painted on foils; the analysis shows that heat leak may be reduced tenfold for surfaces with an α/ϵ of 0.1 compared with gray surfaces. Again, consideration of equivalent heat leaks indicates that the use of approximately 10 times fewer foils of emissivity 0.05 is possible when spectrally selective surfaces are employed. The present state of the art in achieving such surfaces is also briefly reviewed.

Rendezvous capability of horizontal takeoff launch vehicle with air breathing propulsion system