Peter E. Glaser

Pressure effects on postulated lunar materials.

Abstract Literature data on the thermal conductivity of solid, porous, and powder rocks and minerals are reviewed. The line heat source and thermal conductivity probe methods for measurement of thermal conductivity of these materials are described. Experimental data on the effects of pressure from 10 −10 Torr to atmospheric and temperatures from 100° to 400°K on the thermal conductivity of solid, porous, and powder rocks are reported. The results are discussed in terms of possible lunar surface materials.

The Use of a Kaleidoscope to Obtain Uniform Flux Over a Large Area in a Solar or Arc Imaging Furnace

The use of properly designed light pipes to redistribute the energy of a solar furnace or an arc imaging furnace is discussed. Compared to alternate schemes of obtaining uniform irradiation over a large area, the light pipe has the advantage of good uniformity without a serious loss of efficiency. Theoretical analyses concerning the principle of operation, as well as formulas for estimating the flux uniformity and reflection losses, are discussed. The results also indicate that the only suitable cross sections are the square, triangular, hexagonal, and rectangular. Other cross sections, including the circular, are not satisfactory unless used with diffusely reflecting surfaces.

Solar power from satellites

Various alternative energy sources have been proposed in the last few years, many of them figuring in the pages of PHYSICS TODAY. The recognition that no one of these energy sources will, by itself, meet all future power needs, together with the large uncertainties inherent in the achievement of full potential for each of them, has led to what might appear the most daring proposal so far: large‐scale solar‐energy conversion in space with a satellite solar‐power station located in synchronous orbit around Earth—that is, at an altitude of 22 300 miles above the surface.

An overview of the solar power satellite option

The objective of the solar power satellite (SPS) is to convert solar energy in space for use on earth. Its most significant benefit is the potential for continuously generating large-scale electric power for distribution on a global basis. The SPS system is outlined, and the status of the SPS concept development is reviewed. Assessments of key issues are reported including economic considerations and environmental issues as well as physical resource requirements. Legal issues and the need for international agreements on SPS operations are outlined. International SPS-related activities within the context of evolving space programs are discussed. An approach for an evolutionary advancement of SPS to meet requirements for power supplied for use on earth and in space is presented, and a growth path to achieving the potential of power from space for use on earth is outlined. The significance of advancements in technologies applicable to the development of the SPS are discussed. >

The potential of satellite solar power

The role of solar energy is being investigated to establish its potential contributions to meeting future energy demands on a significant national and world scale. This role is briefly reviewed to provide the background for considering the advantages of converting solar energy in space. The technology options for converting solar energy in space and transmitting power to earth are outlined. The design concepts of the SSPS based on thermal-electric and photovoltaic conversion are examined and salient characteristics are provided. Details of microwave power generation, beam transmission, and rectification and utility power pool interfaces are discussed. The requirements for a space transportation system, orbital assembly, maintenance and manufacturing in space are reviewed. The results of economic projections of SSPS operations are presented, utility economics outlined, and institutional impacts and legal status of the use of outer space considered. The environmental impacts of SSPS operations, such as stratospheric pollution by space vehicle exhaust products and of the microwave beam, including atmospheric attenuation and scattering, ionospheric propagation, and microwave biological effects are highlighted. A development program for the SSPS is outlined and critical technology areas which will have to be developed before the SSPS can be commercialized are mentioned.

Units and symbols in solar energy

The application of S.I. units to some common solar energy quantities is discussed and some conversions to S.I. units are given. Then, a list of preferred names, symbols and units is recommended. (SPH)

Engineering research with a solar furnace

Abstract Research approaches using a solar furnace for the measurement of properties of matter and testing of materials at high temperatures under controlled conditions in the laboratory are discussed. Instruments to measure temperatures, heat flux, and flux density are described, and their uses pointed out. Methods for measuring thermal conductivity, thermal expansion, heat content, and emissivity of materials are explained, and the analytical and experimental procedure outlined.

Satellite solar power station

Abstract The finiteness of the Earths fossil-fuel reserves are discussed and the world energy needs are projected to show that alternative energy sources to nuclear power merit consideration. A satellite solar power station is proposed to generate power to meet future requirements. Considerations are given to orbital location, solar energy conversion devices, transmittal equipment and Earth-receiving stations. The use of photoconductive organic materials to form thin film solar collector surfaces and generation of microwave radiation to transmit energy to an Earth-based antenna are discussed. The design considerations and the development tasks for a large satellite solar power station are reviewed and the potential technological needs are identified. The suggestion is made that the technology developed for the space program may find application in a satellite solar power station to generate power for use on Earth.

High Radiation‐Flux, Absolute, Water‐Flow Calorimeter

A high radiation‐flux, measuring calorimeter has been designed for use in imaging furnaces. It consists of a black‐body receiver provided with a cooled aperture and cylindrical housing. It can be exposed to flux densities of the order of 400 cal/cm2 sec for extended periods without deterioration. Thermopiles measure the temperatures of the inlet and outlet cooling water. The calorimeter is an absolute measuring device with a response time of one minute. The design virtually eliminates heat losses and permits the measurement of a wide range of heat fluxes. The probable error in the radiation‐flux measurement is ±5%.

A solar furnace for use in applied research

Abstract A description is presented of a solar furnace developed by Arthur D. Little, Inc. for research use. This furnace was developed to provide a compact, flexible research tool for exposing materials to temperatures up to 3500 °C. over a circular area of 0.6 cm diameter, without the problem of contamination from sample containers or furnace walls. An important feature is the sample-moving mechanism which allows the sample to be moved parallel to any of the three coordinates. Variable-speed motors, the controls for which are conveniently located at the base of the mirror support, permit regulation of the motion of the sample holder. Movement can take place either in cartesian or polar coordinates; and the sample can thus be rotated around the hot zone if desired. Measuring and optical instruments can be inserted through the hole at the back of the reflector and can be placed very close to the hot sample without being affected by the high temperature. An electronic guiding system keeps the furnace trained on the sun, while a shielding cylinder provides temperature control over the sample even at the highest temperature range. This solar furnace is the first in a line of high temperature equipment which Arthur D. Little plans to make commercially available to research laboratories.