Nov 13 1975
From The Space Library
The earth's ozone layer, a shield of heavy molecules of oxygen that prevents some harmful ultraviolet radiation from reaching the earth's surface, might be in less danger from aerosol sprays than from the increasing worldwide use of chemical fertilizers. Michael B. McElroy, professor of atmospheric sciences at Harvard University, had predicted that a projected increase in the use of nitrogen fertilizers over the next 25 yr could reduce the ozone layer 20 to 25%. Theoretically, each 1% reduction in the ozone layer could lead to thousands-as many as 15 000-additional cases of skin cancer in the U.S. alone.
All life needs nitrogen to make proteins, McElroy pointed out. The earth's atmosphere would have lost all its nitrogen long ago except for the process by which bacteria "denitrify" decayed matter in the soil; most nitrogen returned to the atmosphere in the same inert pure form in which it was taken and converted to use by earth's plant life, which then formed a source of nitrogen for other plants and animals; however, some nitrogen returned in a form that acted as a catalyst to destroy ozone. Man had recently been extracting nitrogen from the air and putting it into plant life in the form of fertilizer on a scale rivaling nature; by the year 2000, said McElroy, the amount of nitrogen extracted from the air would be double that removed by natural causes. With a sharp increase in the natural denitrification process, more nitrogen catalysts destructive to ozone would be released. Serious effects should be evident within the next 40 yr, McElroy said. Although aerosol sprays could be dispensed with, nitrogen fertilizers were a necessity for increased world food production. Increased incidence of skin cancer concerned light-skinned humans, who were unlikely to get much sympathy from darker-skinned inhabitants of areas where the fertilizers-and increased food production-are urgently needed. (WSJ, 13 Nov 75, 13)
First major inflight tests of the Viking 1 gander scheduled to touch down on Mars in July 1976 had shown the craft to be in excellent health, flight controllers at Jet Propulsion Laboratory reported. JPL engineers completed thorough checks of the nuclear power, propulsion, guidance, attitude control, computer, tape recorder, telemetry, heat control, and radar landing systems, as well as four of the scientific instruments, including two cameras to photograph the Martian surface in closeup. The second Viking lander, scheduled to reach Mars in Sept. 1976, would undergo similar checkout the following week. (Pasadena Star News, 14 Nov 75, 1)
Calculation of crop acreage from satellite images had proven "generally adequate" in NASA tests involving wheat acreage in nine Great Plains states during the past year, NASA Associate Administrator Charles W. Mathews told the House Subcommittee on Space Science and Applications. Reporting on the 9.9% error rate in the LACIE (large area crop inventory experiment) test using Landsat data, Mathews said that the U.S. had demonstrated the feasibility of an operational global forecasting system for wheat. Mathews mentioned other Landsat data applications: The Geological Survey and NOAA had developed computer techniques for processing multispectral Landsat data that made oil slicks clearly visible. Other computer techniques using the data had detected subtle differences in surface soils and rocks that revealed mineralization and potential ore deposits. (Transcript, Vol I Part 1, 931, 938, 939)
Estimated cost of the Spacelab being built for the first Space Shuttle flight had risen from: $400 million to $500 million during the last year, and the program had fallen 3 to 6 mo behind schedule, NASA's Space lab program director Douglas Lord told the House Subcommittee on Space Science and Applications. The European Space Agency, which was developing Spacelab, was confident of delivering it in time to fly on the Shuttle. Lord and NASA Associate Administrator John F. Yardley said the increased development cost would not affect NASA's cost in purchasing the modules, because NASA's agreement with ESA precluded the Europeans from recouping development costs. NASA had been committed to buying one set of Spacelab hardware at a cost "reasonable to NASA," although pricing proposals would not be received for 6 to 8 mo. The two officials said European cooperation on the program had been "exceptional." (Transcript, Vol I Part l, 889)
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