Dec 16 2004
From The Space Library
An independent panel of experts provided its interim assessment of NASA's efforts to meet the CAIB's requirements for resuming Space Shuttle flights. NASA had chartered the Stafford-Covey Return to Flight Task Group (SCTG) to assess independently its implementation of the CAIB's preflight recommendations ~ mandatory for NASA's resuming Space Shuttle flights. The 26-member Task Group, headed by former astronauts Thomas P. Stafford and Richard O. Covey, stated that it had approved NASA's compliance plans for eight of the CAIB's 15 requirements. The task force did not see any major obstacles to NASA's resuming Shuttle flights by May or June of 2005. The Task Group also noted, however, that NASA continued to have difficulty developing methods to repair the exterior heat tiles and thermal-resistant carbon-fiber material damaged during Shuttle flights. (Warren E. Leary, “Panel Sees Shuttle Flights Resuming Soon,” New York Times, 17 December 2004.
NASA awarded Jacobs Sverdrup a five-year, US$1.2 billion contract to provide engineering and scientific products and support services at NASA's JSC. Under the contract, Jacobs Sverdrup would provide engineering products and services to support the ISS, Space Shuttles, planetary missions, and numerous other NASA programs. In addition, the company would provide those services to JSC's Engineering Directorate and Astromaterials Research and Exploration Science Office. (NASA, “NASA Awards Engineering and Science Contract,” news release c04-dd, 16 December 2004.
A NASA-funded study provided the first direct evidence that aerosols affect the absorption and release of carbon by ecosystems. Because carbon, in the form of carbon dioxide in the atmosphere, acts as a heat-trapping greenhouse gas, the research team sought to identify the factors that influence carbon transfer between the atmosphere and soils. Led by Dev S. Niyogi of North Carolina State University, the scientists had used NASA satellite data to examine atmospheric aerosol content and carbon absorption in different ecosystems. They had discovered that high aerosol levels increase carbon absorption in croplands and forests but decrease carbon absorption in grasslands. The researchers suggested that this variation occurs because of the way that aerosols interact with different types of vegetation canopies to affect the dispersion of radiation from sunlight. In the dense vegetation canopies of croplands and forests, aerosols scatter sunlight in a manner that enables more radiation to reach a greater quantity of plant leaves and increases carbon absorption through plant photosynthesis. However, in the less dense vegetation canopy of grasslands, aerosols scatter sunlight in a manner that raises ground temperatures, causing the soil to release more carbon dioxide. (NASA, “NASA Study Finds Tiny Particles in Air May Influence Carbon Sinks,” news release 04-394, 16 December 2004; D. Niyogi et al., “Direct Observations of the Effects of Aerosol Loading on Net Ecosystem CO2 Exchanges over Different Landscapes,” Geophysical Research Letters 31, no. 20 (29 October 2004): L20506.
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