Nov 15 1985
From The Space Library
NASA's Lewis Research Center (LeRC) announced it had awarded a total of $8.7 million in contracts to Sundstrand Corp., Grumman Aerospace Corp., Boeing Aerospace Co., and Harris Corp. for advanced development contracts for definition and preliminary design (Phase B) of the power system for the proposed permanently manned space station.
A major technical issue in Phase B was determination of whether photovoltaic arrays or a solar dynamic (heat engine) system should supply solar-generated power for the space station. Photovoltaic arrays were the accepted system for electricity production in manned and unmanned space missions. However, the space station's electrical power requirements were ten times greater than any mission flown to date and would necessitate arrays of approximately one-half acre for the initial station. Therefore, there was interest in solar dynamic systems because of their higher overall efficiency and relatively smaller size.
In a solar dynamic system, an alternator driven by a turbine in a heat engine cycle produces electricity. Focusing the sun's rays by means of a concentrating mirror into a heat receiver heats the engine gas or liquid. The system operates as a closed-cycle heat engine, and a radiator cools the working fluid and rejects waste heat into space.
Sundstrand Corp., under its $1,010,303 cost-plus-fixed-fee contract, would study the magnitude of possible chemical and thermal degradation in the working fluid of an organic rankine cycle engine. Under its $1,010,000 cost-reimbursement contract, Grumman would study solar dynamic waste heat radiator technology. Boeing Aerospace Co., under its $3,117,059 cost-plus fixed-fee contract, would study the heat receiver/storage unit and identify and recommend testing required for concept verification. And Harris Corp., under its $3,619,870 cost-sharing contract, would generate conceptual designs for the solar dynamic dish concentrator, as well as identify and test materials, identify and recommend testing required for concept verification, perform engineering designs, fabricate the concentrator, and conduct verification and testing. (LeRC Release 85-77)
NASA's Inventions and Contributions Board awarded the Jet Propulsion Laboratory's (JPL) Dr. Robert Nathan a plaque and a check for $20,000 for his work in planetary image processing, the JPL Universe reported. Nathan received the award for his "combined technical contributions to planetary and biomedical image processing and scientific data analysis techniques." Nathan invented digital image processing, a technique in which computers remove noise, correct distortions, and enhance different images such as planetary objects or biomedical images.
Nathan joined JPL in 1959 to manage scientific data analysis for the upcoming Ranger moon missions. The Ranger spacecraft used the best available cameras, but they were subject to distortion and noise contamination. Nathan devised techniques to eliminate extraneous patterns from the images. His processes and the creation of the image processing laboratory (IPL) established JPL as an important center for planetary image processing.
In 1969 Nathan launched JPL into biomedical imaging with a $2 million grant from the National Institutes of Health, which later led to formation of the JPL biomedical image analysis facility.
In 1976 Nathan developed a system at the IPL to handle large amounts of data by means of a large array filter using very-large scale integration (VLSI) system silicon chip technology. The microchip reduced computer time by a factor of 100.
He was currently working on another microchip design that would perform high-quality geometric image manipulations and filter chips that would perform pattern recognition functions. (JPL Universe, Nov 15/85, 1)
Nobel Laureate Charles Townes, speaking recently at a Smithsonian Institution Associates lecture, discussed how he and his colleagues at the University of California-Berkeley proved, after years of hypothesizing and researching, that there was a black hole, twice the size of the sun and four million times as heavy, in the center of our galaxy, the Milky Way, the Washington Times reported.
A black hole is a body of such enormous gravity that nothing escapes it-no light waves, no radio waves, no waves of any kind-and it cannot, by definition, be seen or heard. Townes said he and his colleagues identified the black hole by deductive reasoning and picking up clues here and there.
The first clue came in the 1940s when a scientist at Bell Laboratories picked up a steady stream of radio noise from roughly the center of the Milky Way. Electrons bumping into protons and heating them produced radio waves, but great permanent clouds of silicate dust obscured the radio wave source. Several decades later scientists at Berkeley detected infrared waves coming from the same place. The waves were just long enough to get through the dust clouds, seeming to indicate they came from a cluster of stars.
About ten years before, the scientists picked up gamma rays-a sure sign that, somewhere near the galactic center, antimatter (protons) was destroyed at a rate of about 10 million tons a second. Black holes sucked in stars, causing them to spiral in a whirling cluster, moving faster and faster until they reached the speed of light and were ripped apart and swallowed, a process that created great waves of energy. "That suggested that something very strong and violent was going on," Townes said.
"There were three possibilities," Townes said. "A large cluster of stars, alone, which pulled everything into it, a black hole, or some combination of the two." If it was a cluster of stars, they would all travel at the same speed. If it was a spiral of stars in the process of falling into a black hole, the ones nearest the hole would move a lot faster than those on the outer edge.
Since each element had its own spectrum, an astronomer using a radio telescope could search and find the identifiable wave emitted by a particular element. The astronomers at Berkeley picked out molecules of neon along the line of stars around the galactic center; those furthest from the center were going at the slowest rate, those nearest at the fastest. That proved the presence of a black hole.
Yet to be definitively answered, Townes said, were such questions as whether black holes came in different sizes; whether every galaxy had a black hole at its center; and how it all would end, since black holes were destroying stars. "It's possible," Townes said, "that eventually the black hole will pull in all the stars in our galaxy, if something else doesn't happen first. It would take an enormous time, so far in the future, that all kinds of other things would be more likely to happen. Such as our sun cooling off. We're more likely to fall into the sun than into the black hole. I don't think we have to worry about that immediately." (W Times, Nov 15/85, C1)
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