Suchergebnisse

Termination of U.S. government support for the Supersonic Transport, SST, may eventually cost the United States its leadership in aviation and billions of dollars in international trade losses, yet if the world wide SST program is allowed to continue, the costs to mankind as a result of damage to environmental resources could be much higher. The decision to terminate the project was heavily based upon concern for possible changes in the properties of the upper atmosphere as a result of SST operations in that realm, with consequent danger to plant and animal life on the Earth below. Briefly, the concern over atmospheric modification stems from pollution from the SST's and possibly other sources. The SST's must operate within the stratosphere to reduce the danger from sonic booms and to obtain high operating efficiency. Because that region is very stable (little mixing occurs), pollutants from the SST exhausts, will accumulate in the stratosphere and impurities will remain in that region for at least a year and possibly several years. Two very great dangers can be visualized from stratospheric pollutants. First, the temperature of the Earth may be increased or decreased by greater or lesser retention of solar energy- a change either way could change the Earth's ability to support life. Second, and perhaps most important, the ozone within the atmosphere, which now blocks most of the Sun's ultraviolet rays, could be reduced by pollutants thus allowing the rays to penetrate to the Earth's surface causing skin cancer, blindness, and other serious biological effects