KFL@MIT-MC.ARPA ("Keith F. Lynch") (12/30/85)
From: unmvax!nmtvax!wildstar@ucbvax.berkeley.edu Has anyone ever thought about the environmental impact that an air- breathing x-atmos vehicle is likely to cause? ...what would happen to the atmosphere if it is relied on as oxidizer? Not much. The amount of oxygen in the atmosphere is enormous. Since the fuel would probably be hydrogen, the only combustion product would be water vapor. Since the hydrogen for the fuel was gotten from water in the first place, there is really no net change to the environment. The great heat of the combustion could cause some nitrogen and oxygen in the atmosphere to combine to form trace amounts of nitrogen oxides. This is the same thing that happens whenever there is lightning. And the energy in one fair-sized thunderstorm is far more than the energy of a shuttle launch. The fuel needs of the trans-atmospheric vehicle would be far less than that of a vehicle which has its oxidizer on board. And every space vehicle, to date, has burned the most and the fastest, when closest to the ground. And I have never heard of any adverse effects from the combustion, except for temporary heating of the ground (along with any unfortunate small animals) within a mile or two of the launch pad. In particular, I have never heard of any acid rain problem in southern Florida, or any pollution problem there that has anything to do with the space program. If you are concerned about acid rain, it is better to worry about the billions of tons of sulfur-rich coal that are burned every year in the midwest than to worry about the thousands of tons (millions of times less) of clean rocket fuel burned each year. The Orion program was cancelled largely due to environmental concerns. The Orion program proposed launches to be made by detonating hundreds of nuclear bombs. Had this program continued, we would probably have the solar system in our grasp today. We would also have several thousand extra fatal cancers. It was decided that it was not worth it. I agree with that decision. Though it should be pointed out that smoking causes about 100 times the deaths that Orion would have. Environmentalists did us all a service by forcing Orion to be cancelled. But if environmentalists object to everything, they quickly lose their credibility. Expansion into space is necessary for the future of our species. Without space, we are all doomed. Blind opposition to all forms of space travel is counter-survival. If environmentalists wish to improve our environment, they should concern themselves primarily with smoking. Automobiles and alcohol would be tied for a distant second. And burning coal would be a very distant third. Nothing else is even in the running. ...Keith
dietz@SLB-DOLL.CSNET (Paul Dietz) (12/30/85)
It should be pointed out that while a fair-sized thunderstorm has more energy than a shuttle launch, a scramjet powered launcher will be doing most of its combustion in the upper atmosphere, right in the ozone layer. The thunderstorm's NOx gets produced in the troposphere and washes out quickly, so the comparison is not entirely fair. Paul Dietz
space@ucbvax.UUCP (01/02/86)
In article <[MC.LCS.MIT.EDU].768142.851229.KFL> you write: > If environmentalists wish to improve our environment, they should >concern themselves primarily with smoking. Automobiles and alcohol >would be tied for a distant second. And burning coal would be a very >distant third. Nothing else is even in the running. > ...Keith I think you are equating improving the environment with reducing the death rate of humans. This is not the main thrust of the environmental movement. Improving the quality of human life and maintaining a balanced ecosystem are closer to the goals as I see them. Automobiles are certainly a problem here, but tobacco, autos and alcohol are primarily human health risks. If you really want something to worry about in the realm of both environmental quality and human health, consider the future of the water resources of the planet. Nemo -- Internet: nemo@rochester.arpa UUCP: {decvax, allegra, seismo, cmcl2}!rochester!nemo Phone: [USA] (716) 275-5766 school 232-4690 home USMail: 104 Tremont Circle; Rochester, NY 14608 School: Department of Computer Science; University of Rochester; Rochester, NY 14627