been conducted and a nominal date for the first suborbital test flight was sometime in July. The vehicle is being built by G.C.H., Inc. under contract to Space Services, Inc. There followed two papers on large space structures: one by Ray Sperber considering compressional structures and one by Rand Simberg contemplating a weblike structure around the entire geosynchronous orbit, held in place by gravity gradient forces. The web could be used as a support frame for what would otherwise be independently orbiting GEO satellites. This would eliminate collision possibilities. Simberg stated that this web concept is consistent with present or near term technology and materials. E. C. Okress and R. K. Soberman presented an interesting paper describing a Solar Powered Stratospheric Platform (SPSP). The platform would consist of a lighter than air balloon several hundred meters in diameter. The most likely gas would be hot air heated by the greenhouse effect through a double-walled transparent top. Other lifting gases such as He and H2 have been considered. The device could have a payload of 105 kg and at least a three year lifetime with no resupply necessary. It could be manned or unmanned and hover to a positional accuracy of 12 km with east or west drift capability of up to 10 knots. The device could satisfy needs for a stable high altitude platform with a long lifetime and high payload capability. Possible applications include the use as a platform for an SPS rectenna or as a solar energy collector with the power returned to Earth by microwaves. The evening session ended with two papers on unusual space telescopes. R. L. Frost and J. E. Beckman described the benefits of mounting a telescope on a small (10 km diameter) asteroid; namely, the asteroid can provide substantial inertial mass for high pointing accuracy without much gravitational force to hinder construction and support requirements. A telescope with a mirror 250 m in diameter could resolve a planet at 50 pc. Eric C. Hannah discussed using the sun or a similar star as a gravitational lens for the ultimate telescope. The focus would be at 1000 a.u., but the telescope could resolve an Earth-sized planet in Andromeda. David R. Criswell chaired the Wednesday morning session on Materials, Resources, and Purchasing. Professor John W. Freeman, who had to leave early, discussed the Space Foundation and Space Solar Power Review. Professor Freeman also gave a brief progress report on research on the photoron (photoklystron), a device that converts light directly to RF energy. He indicated device efficiencies as high as about 1% at frequencies of 200 MHz have now been obtained and the prospects look good for further improvement. Professor James R. Arnold spoke for John Carruthers on “NASA Planning for Space Materials Industry.” Professor Arnold said that one of Robert Frosch's last acts before resigning from his post as NASA administrator had been to establish a materials processing division in NASA with Carruthers in charge, and a Solar System Exploration Committee of which Professor Arnold and Marty Gluckman were members. William N. Agosto of Rutgers University presented a paper on “Beneficiation and Powder Metallurgical Processing of Lunar Soil Metal.” He said that the value of a material has to do with its accessibility and that many metallic ores on the Moon can be picked up with a magnet. Magnetic concentration of ore, he said, is a very mature technology and rotary drum separators using permanent magnets and motors drawing only 2-3 kW would be effective on the Moon. He suggests centrifugal drivers (impact grinding), screening, and magnetic drum separators. He said that about 38 tons of equipment would be needed on the Moon to process 116 tons of lunar soil per hour. The output over a year would be 100 times the weight
RkJQdWJsaXNoZXIy MTU5NjU0Mg==