esm1@quads.uchicago.edu (Eric S. Mendelsohn) (10/19/90)
I'm sorry if this subject has been discussed to death, but I'm new to this news group and couldn't find many old posts. If someone has a collection of answers to these questions, please e-mail 'em and earn my gratitude! I heard the other day that each shuttle launch releases an enormous quantity of ozone-destroying gasses into the upper atmosphere, and according to one (believable?) study, the current flight schedule will cause 10% of the pro- jected ozone depletion in the next 5 (or 10?) years. Anyone know the facts about what the shuttle dumps out in a typical flight? Is anyone concerned about the impact of these discharges? Is there an alternative fuel that would have less environmental impact without requiring a major redisign? Realistic- ally, will these issues even be considered by NASA? ------------------------------------------------------------------------------- Eric Mendelsohn When all is said and done, Internet: esm1@midway.uchicago.edu More is said than done.
draper@cps3xx.cps.msu.edu (Patrick J Draper) (10/20/90)
In article <1990Oct19.022310.14985@midway.uchicago.edu> esm1@quads.uchicago.edu (Eric S. Mendelsohn) writes: >I'm sorry if this subject has been discussed to death, but I'm new to this news >group and couldn't find many old posts. If someone has a collection of answers >to these questions, please e-mail 'em and earn my gratitude! > >I heard the other day that each shuttle launch releases an enormous quantity >of ozone-destroying gasses into the upper atmosphere, and according to one >(believable?) study, the current flight schedule will cause 10% of the pro- >jected ozone depletion in the next 5 (or 10?) years. Anyone know the facts >about what the shuttle dumps out in a typical flight? Is anyone concerned >about the impact of these discharges? Is there an alternative fuel that would >have less environmental impact without requiring a major redisign? Realistic- >ally, will these issues even be considered by NASA? > >------------------------------------------------------------------------------- >Eric Mendelsohn When all is said and done, >Internet: esm1@midway.uchicago.edu More is said than done. Let's see now..... The shuttle burns H2 as fuel (hydrogen). The oxidizer is O2 (oxygen). If I'm correct, the reaction is thus: 2H + O ---> H O (water) 2 2 2 I doubt that mother earth minds too much. Patrick Draper ------ Michigan State University
eric@abode.UUCP (Eric C. Bennett) (10/20/90)
In article <1990Oct20.073254.23197@msuinfo.cl.msu.edu> draper@cps3xx.cps.msu.edu (Patrick J Draper) writes: >Let's see now..... >The shuttle burns H2 as fuel (hydrogen). The oxidizer is O2 (oxygen). >If I'm correct, the reaction is thus: > > 2H + O ---> H O (water) > 2 2 2 > >I doubt that mother earth minds too much. I believe he is talking about the solid rocket booster engines. I have heard something about them affecting the ozone layer, but I don't know to what degree. Eric -- Eric C. Bennett uucp: {elroy|cit-vax}!wciu!abode!eric El Monte, Ca Internet: eric@abode.wciu.edu If you can read this you aren't looking through the hubble space telescope!
dil@mace.cc.purdue.edu (Perry G Ramsey) (10/21/90)
In article <1990Oct20.073254.23197@msuinfo.cl.msu.edu>, draper@cps3xx.cps.msu.edu (Patrick J Draper) writes: > In article <1990Oct19.022310.14985@midway.uchicago.edu> esm1@quads.uchicago.edu (Eric S. Mendelsohn) writes: > >I heard the other day that each shuttle launch releases an enormous quantity > >of ozone-destroying gasses into the upper atmosphere, and according to one > > Let's see now..... > The shuttle burns H2 as fuel (hydrogen). The oxidizer is O2 (oxygen). > If I'm correct, the reaction is thus: > > 2H + O ---> H O (water) > 2 2 2 > > I doubt that mother earth minds too much. There is a lot more to it than this. The solids produce a large quantity of nasty stuff, including chlorine compounds. Chlorine normally has a tough time getting into the stratosphere (where the ozone is), but a Shuttle launch is a great source. (So are chlorofluorocarbons. That's the problem with them.) I believe the conclusion of our discussions is that this is a problem. How big? More than insignificant, but less than a few ecohysteric tree-huggers would like everyone to believe. -- Perry G. Ramsey Department of Earth and Atmospheric Sciences perryr@vm.cc.purdue.edu Purdue University, W. Lafayette, IN USA dil@mace.cc.purdue.edu We've looked at clouds from ten sides now, And we REALLY don't know clouds, at all.
daveb@athena.mit.edu (Dave Balkwill) (10/22/90)
This is a repost of an article from a couple of months back that I saved from the net. I hate to do this, but before the discussion gets out of hand, here are some facts and figures. Dave ------------ From bloom-beacon!bu.edu!rpi!zaphod.mps.ohio-state.edu!sdd.hp.com!elroy.jpl.nasa.gov!ames!dftsrv!cdc910b21.gsfc.nasa.gov!newman Mon Aug 13 02:08:24 EDT 1990 Article 6200 of sci.space.shuttle: Xref: bloom-beacon sci.space.shuttle:6200 sci.chem:1617 sci.environment:7900 sci.space:23253 Path: bloom-beacon!bu.edu!rpi!zaphod.mps.ohio-state.edu!sdd.hp.com!elroy.jpl.nasa.gov!ames!dftsrv!cdc910b21.gsfc.nasa.gov!newman >From: newman@cdc910b21.gsfc.nasa.gov (P.A. Newman) Newsgroups: sci.space.shuttle,sci.chem,sci.environment,sci.space Subject: Re: Space Shuttle Destroys Ozone Layer ??? Keywords: ozone, shuttle, titan Message-ID: <3071@dftsrv.gsfc.nasa.gov> Date: 9 Aug 90 14:55:52 GMT References: <32493@cup.portal.com> Sender: news@dftsrv.gsfc.nasa.gov Reply-To: newman@cdc910b21.gsfc.nasa.gov (P.A. Newman) Organization: NASA Goddard Space Flight Center, Greenbelt MD Lines: 65 On 6 Aug 90 mmm@cup.portal.com (Mark Robert Thorson) wrote: >The current issue of Buzzworm, an "environmental journal" has a short article >on page 14 describing the pollution effects of the space shuttle. Quoting >from vol 2 no 4 (probably one of the last issues of this high-overhead glossy >rag): > ... >Huh? Could any of these figures possibly be true? If Space Shuttle >launches might cause 10% or even 1% of the ozone problem, that seems >like a serious cause for concern! I rather suspect somebody must have >slipped a few digits in reporting this story. Can somebody please provide >some real numbers on how much the Space Shuttle contributes to the ozone >problem. ************************** I talked to Charlie Jackman (one of the authors of the above quoted study) and his response follows: ************************** The atmospheric modelling study of the space shuttle effects on the stratosphere involved three independent theoretical groups, and was organized by Dr. Michael Prather, NASA/Goddard Institute for Space Studies. The three groups involved Michael Prather and Maria Garcia (NASA/GISS), Charlie Jackman and Anne Douglass (NASA/Goddard Space Flight Center), and Malcolm Ko and Dak Sze (Atmospheric and Environmental Research, Inc.). The effort was to look at the effects of the space shuttle and Titan rockets on the stratosphere. The following are the estimated sources of stratospheric chlorine: Industrial sources: 300,000,000 kilograms/year Natural sources: 75,000,000 kilograms/year Shuttle sources: 725,000 kilograms/year The shuttle source assumes 9 space shuttles and 6 Titan rockets are launched yearly. Thus the launches would add less than 0.25% to the total stratospheric chlorine sources. The effect on ozone is minimal: global yearly average total ozone would be decreased by 0.0065%. This is much less than total ozone variability associated with volcanic activity and solar flares. The influence of human-made chlorine products on ozone is computed by atmospheric model calculations to be a 1% decrease in globally averaged ozone between 1980 and 1990. The influence of the space shuttle and Titan rockets on the stratosphere is negligible. The launch schedule of the Space Shuttle and Titan rockets would need to be increased by over a factor of a hundred in order to have about the same effect on ozone as our increases in industrial halocarbons do at the present time. Theoretical results of this study will be published in the Journal of Geophysical Research in the next few months in the paper "The Impact of the Space Shuttle on Stratospheric Chemistry and Ozone" by M. J. Prather, M. M. Garcia, A. R. Douglass, C. H. Jackman, M. K. W. Ko, and N. D. Sze. Charles Jackman, Atmospheric Chemistry and Dynamics Branch, Code 916, NASA/Goddard Space Flight Center, Greenbelt, MD 20771 *********************** P. A. Newman Code 916 NASA/GSFC -- ------ daveb@space.mit.edu OR wonko@athena.mit.edu --------- | "In Sweden, we play soccer in weather like this, in shorts." | | -- Bjorn Nittmo, kicker for NFL New York Giants | ----- DISCLAIMER: Of course they're only my opinions! --------
gregc@cimage.com (Greg Cronau) (10/23/90)
In article <1990Oct19.022310.14985@midway.uchicago.edu> esm1@quads.uchicago.edu (Eric S. Mendelsohn) writes: >I'm sorry if this subject has been discussed to death, but I'm new to this news >group and couldn't find many old posts. If someone has a collection of answers >to these questions, please e-mail 'em and earn my gratitude! > >I heard the other day that each shuttle launch releases an enormous quantity >of ozone-destroying gasses into the upper atmosphere, and according to one >(believable?) study, the current flight schedule will cause 10% of the pro- >jected ozone depletion in the next 5 (or 10?) years. Anyone know the facts Yes, this subject was done to death awhile back. The facts, as I understand them, are: 1.) Clourine (CL) can destroy ozone by combining with it. 2.) CFCs (ClouroFlouroCarbons) can destroy ozone at a *MUCH* greater rate due to the fact that the mechanism by which CFCs destroy ozone is catalytic. That is, the CFCs are NOT consumed by the reaction, and a given CFC molecule can destroy many ozone molecules before it is itself destroyed by other processes. I believe that a given quantity of CFC has several orders of magnitude more destructive capacity than the same quanity of CL, when it comes to the break-down of ozone. 3.) The shuttle's SRBs produce Hydroclouric acid (HCL) *NOT* CFCs. 4.) The writer of the report failed to make any distiction between the HCL released by the SRBs and the ozone damage caused by CFCs. He treated CFC and HCL as equally damaging. In short, in the opinion of most of the people on the net, the report had no basis in fact. gregc@cimage.com
awesley@egrunix.UUCP (Tony Wesley) (10/24/90)
In article <1990Oct23.030624.7555@cimage.com> gregc@dgsi.UUCP (Greg Cronau/10000) writes: >The facts, as I understand them, are: >1.) Clourine (CL) can destroy ozone by combining with it. >2.) CFCs (ClouroFlouroCarbons) can destroy ozone at a *MUCH* greater rate due > to the fact that the mechanism by which CFCs destroy ozone is catalytic. > That is, the CFCs are NOT consumed by the reaction, and a given CFC > molecule can destroy many ozone molecules before it is itself destroyed > by other processes. I believe that a given quantity of CFC has several > orders of magnitude more destructive capacity than the same quanity of CL, > when it comes to the break-down of ozone. This is incorrect. CFCs do not break down ozone. CFCs react with virtually nothing -- their inertness is the major reason they are used. When CFCs reach high altitude, UV can knock the Clorine molecule off the CFC. Clorine is what causes the damage. The Cl reacts with the ozone in a catalytic fashion. The reactions that occur are: Cl + O -> ClO + O 3 2 and ClO + O -> Cl + 2O 3 2 which leaves our Cl atom to go back and do it again. CFC is merely a mechanism to get Cl into the upper atmosphere. I learned much about this from a book by Isaac Asimov, _The Planet That Wasn't_. The chapters "The Smell of Electricity," "Silent Victory," and "Change of Air" deal with the ozone layer and the mechanism by which CFCs reduce it. >3.) The shuttle's SRBs produce Hydroclouric acid (HCL) *NOT* CFCs. See above. This is not relevent. >4.) The writer of the report failed to make any distiction between the HCL > released by the SRBs and the ozone damage caused by CFCs. He treated CFC > and HCL as equally damaging. >In short, in the opinion of most of the people on the net, the report had no >basis in fact. I don't recall this conclusion being reached for the reasons you state. If I recall properly, the reason the shuttle wasn't very dangerous to the ozone layer was because it didn't release that much Cl, and that is primarily because the shuttle doesn't fly very much. >gregc@cimage.com -- And little Sir John with his nut brown bowl Tony Wesley/RPT Software And his brandy in the glass voice: (313) 274-2080 And little Sir John with his nut brown bowl awesley@unix.secs.oakland.edu Proved the strongest man at last... Compu$erve: 72770,2053
petej@phred.UUCP (Pete Jarvis) (10/24/90)
In article <1990Oct20.073254.23197@msuinfo.cl.msu.edu> draper@cps3xx.cps.msu.edu (Patrick J Draper) writes: >Let's see now..... >The shuttle burns H2 as fuel (hydrogen). The oxidizer is O2 (oxygen). >If I'm correct, the reaction is thus: > 2H + O ---> H O (water) > 2 2 2 >I doubt that mother earth minds too much. >Patrick Draper ------ Michigan State University The Shuttle also has 2 very hot Solid Rocket Boosters. Peter Jarvis
dil@mace.cc.purdue.edu (Perry G Ramsey) (10/24/90)
In article <1990Oct23.030624.7555@cimage.com>, gregc@cimage.com (Greg Cronau) writes: > In article <1990Oct19.022310.14985@midway.uchicago.edu> esm1@quads.uchicago.edu (Eric S. Mendelsohn) writes: > >I heard the other day that each shuttle launch releases an enormous quantity > >of ozone-destroying gasses into the upper atmosphere, and according to one > In article <1990Oct23.030624.7555@cimage.com>, gregc@cimage.com (Greg Cronau) writes: > Yes, this subject was done to death awhile back. > The facts, as I understand them, are: > 1.) Clourine (CL) can destroy ozone by combining with it. > 2.) CFCs (ClouroFlouroCarbons) can destroy ozone at a *MUCH* greater rate due > to the fact that the mechanism by which CFCs destroy ozone is catalytic. > That is, the CFCs are NOT consumed by the reaction, and a given CFC > molecule can destroy many ozone molecules before it is itself destroyed > by other processes. I believe that a given quantity of CFC has several > orders of magnitude more destructive capacity than the same quanity of CL, > when it comes to the break-down of ozone. > 3.) The shuttle's SRBs produce Hydroclouric acid (HCL) *NOT* CFCs. Definitions: Troposphere: The lower 10 km or so of the atmosphere. There is relatively efficient mixing of the troposphere Stratosphere: The region above the troposphere. There is little exchange between the stratosphere and troposphere. The ozone layer is in the stratosphere. Free chlorine in the stratosphere is the problem. Under most circumstances, it is difficult for chlorine to get up that high, principally because it forms a variety of water soluble compounds and gets washed back down. CFC's are stable and can get that high, where they are broken down by UV and release free chlorine. The chlorine catalyzes the destruction of ozone in a manner similar to the that listed in point 2. This free chlorine is usually removed from the stratosphere when it combines with water to make HCl. The HCl is then scavenged by water and drops to the troposphere. The shuttle, on the other hand, deposits a large quantity of stuff directly into the stratossphere. The SRB's don't produce CFC's, but I'm not convinced that they only produce HCl. Not an expert on stratospheric chemistry:
awesley@egrunix.UUCP (Tony Wesley) (10/25/90)
In article <1990Oct24.152800.12636@uokmax.ecn.uoknor.edu> sally@uokmax.ecn.uoknor.edu (Sally Roberts) writes: (I wrote) >>Clorine is what causes the damage. The Cl reacts with the ozone in a ^^^^^^^ [note the spelling, Sally!] >Oh, and of course, that little fluorine atom is completely innocent!! After ^^^^^^ >all, fluorine is just one of the most reactive elements ever discovered, and ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [precisely!] >only bonds with everything it can get a hold on. Halogens of all sorts do this >to some extent, of course, but fluorine, not chlorine, is the worst. Pure >fluorocarbons, I believe, are more damaging than chlorofluorocarbons. Oh? >............................................................If anyone >really wants them, I can find statistics on which halogenated carbons cause >the most damage. You don't hear as much about fluorocarbon damage anymore >because their use has been banned, while CFC's are still permitted to some >extent, although they too are on the way out. Perhaps there's a reason why the >fluorocarbons were banned first? and perhaps there's also a reason why people >aren't as worried about HCl as they are about CFCs? CFCs are definitely worse. They are?? I would like to see the statistics. Yes, Fluorine is extremely reactive, more so than clorine. From what I understood Asimov to write, F clings to the Carbon so tightly that UV does not knock it loose, while the Cl can be knocked loose. Therefore, CFCs do not deliver Fluorine to the upper atmosphere. One of the reasons Isaac mentions is that the F atom is small (the "little fluorine atom" you mention) while the Cl atom is larger and gets in the way. Let me quote Asimov "the bonds holding the carbon and fluorine atoms together are so tight that almost nothing will budge them. Fluorocarbons will not burn, dissolve in water, or react with almost anything." " . . .ultraviolet light, which is more energetic than ordinary light, is energetic enough to break clorine atoms away from the Freon molecule." "It is thereofre difficult to get very any large chlorocarbons . . . " ". . . fluorocarbons could be formed much more easily than any of the other halocarbons and would involve long carbon chains." >BTW, people, note that the correct spelling of Cl is chlorine, not cluorine. >Just because it sounds like fluorine doesn't mean that you spell it the same >way!!Also note that it's fluorine, not flourine. Please, people, if you're >going to go around ranting about other people's mistakes, at least rant >correctly. Yes, Sally, please rant correctly. I try not to rant, myself. Hopefully, I was giving correct information. At least I gave a source, while you give none. I am open to correction if you have any sources of contrary information. I also wrote: >>catalytic fashion. The reactions that occur are: > >> Cl + O -> ClO + O >> 3 2 > >> and > >> ClO + O -> Cl + 2O >> 3 2 Now lets try this with Fluorine. F + O -> FO + O 3 2 and FO + O -> F + 2O ???! 3 2 I'm not a chemist, but I don't understand how "one of the most reactive elements" is going to free itself up in the second equation. Repeating source of information: >>I learned much about this from a book by Isaac Asimov, _The Planet That >>Wasn't_. The chapters "The Smell of Electricity," "Silent Victory," and >>"Change of Air" deal with the ozone layer and the mechanism by which CFCs >>reduce it. -- And little Sir John with his nut brown bowl Tony Wesley/RPT Software And his brandy in the glass voice: (313) 274-2080 And little Sir John with his nut brown bowl awesley@unix.secs.oakland.edu Proved the strongest man at last... Compu$erve: 72770,2053
melkor@wpi.WPI.EDU (A Soldier Of God) (10/25/90)
Well, there is a very good scapegoat for the ozone problem of the STS SRMs, back in the early 70s, Casper Wienberger was assigned the responsibility of advising Nixon what type of shuttle would be flown. Good old Cap decided to go for the cheap design and production and expensive maintenance idea of the SRM boosters. The other idea on the table at the time was a LOX re-usable system including re-usable tanks. Had he done the intelligent thing and recommended the LOX design, not only would the launch system be cheaper in the long run, but would have been much less of a polluter. Another example of political influence over winning out over common sense. _______________________________________________________________________________ |L.T.N.A.T. (Love Thy Neighbor As Thyself) S..G.L.Y.&S.D.I. (Smile.....) | | "He died for me. I'll live for him" (D&K)| |SSSS CCCC H H L EEEE TTT ZZZZ melkor@wpi.wpi.edu | |S C H H L E T Z The Domino's Dude | |SSSS C HHHH L EEE T Z "I won't go underground/I won't turn and | | S C H H L E T Z flee/I won't bow the knee" PETRA | |SSSS CCCC H H LLLL EEEE T ZZZZ (508) 792-3745 Dominos: 791-7760 | -------------------------------------------------------------------------------