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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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All sourcesNASA NTRSDOE OSTI
NASA NTRS1967

Process sequence produces strong, lightweight reflectors of excellent quality

Large compound curved surfaces for collecting and concentrating radiation are fabricated by the use of several common machining and forming processes. Lightweight sectors are assembled into large reflectors. With this concept of fabrication, integrally stiffened reflective sectors up to 25 square feet in area have been produced.

Reader, A. F.↗
NASA NTRS1967

Flight computers and sequencers

At present, the most common method of increasing reliability of a system against permanent random component failures is to triplicate the entire system and use voters. This method, though it enhances the reliability, does exact a heavy toll in weight and power consumption which increase by about 225%. In the future, computers will be required to perform complex tasks under adverse conditions on surfaces of planets for long periods of time (6 months or more), without any human intervention. At the same time there will be severe limitations on the weight and power consumption of these computers. For such systems it is obvious that simple triple-redundancy will not do. A more efficient and sophisticated design in redundancy has to evolve. This study has been directed toward that goal. It is understood that the initial design of such a system will be too complex and expensive to be used in a commercial computer; but for a space computer, reduction in weight (without reducing reliability) of every ounce means a great deal.

REDUNDANCY↗