Date: Sat, 14 Oct 1989 22:33-EDT From: space-tech-request@cs.cmu.edu To: "~/st/lists/stdigest" Subject: Space-tech Digest #39 Contents: Dick King Re: Orbital Debris Dave Rickel Re: Orbital Debris Al Viall Martian Atmosphere Henry Spencer Re: Martian Atmosphere Paul Dietz Re: Martian Atmosphere Henry Spencer Re: Martian Atmosphere Tero Siili Re: Martian Atmosphere Matt Sisk Martian soil Tero Siili Re: Martian soil John Roberts Re: Martian soil Henry Spencer Re: Martian soil ------------------------------------------------------------ Date: Sat, 07 Oct 89 09:35:30 PDT From: king@kestrel.edu To: CS.CMU.EDU!space-tech@uunet.uu.net Subject: Re: Orbital Debris One problem with catching debris with mylar panels is drag. -dk ------------------------------ Date: Sat, 7 Oct 89 18:05:25 PDT From: Dave Rickel To: space-tech@CS.CMU.EDU Subject: Re: space junk I like the idea of the laser. The military ought to like it too. "No, we're not testing SDI. We're performing a public service". Using ice for a target for small enough particles is kind of interesting (where small enough falls in a fairly small range--large enough to do damage, but small enough that if it fractured into pieces, the pieces wouldn't do too much damage). Unfortunately, i don't think there's any way of tracking particles that small. Any pieces that got knocked off your ice lump would sublimate fairly quickly, so your target wouldn't contribute too much to the problem. I like the idea of using foamed ice myself--the pieces of ice that get knocked off will be much smaller, you can get a bigger target for the same amount of mass, and i like the idea of knocking space junk down with snowballs. david rickel decwrl!sci!daver ------------------------------ From: Al Viall Subject: Martian Atmosphere To: space-tech@CS.CMU.EDU Date: Sat, 7 Oct 89 17:09:19 CDT Disclaimer: The views shown by this writer are not his at all. Oper. Sys.: Running Pyramid OSx4.4 on a 9815 and 98XE X-Mailer: ELM [version 2.2 PL11] Not meaning to swing discussion around 180 degrees but I was wondering something. Having to do with the martian atmosphere; what is it's chemical makeup, such as percent of CO2 and other elements. And, if the is ANY O2, how much? We all know that it is primarily comprised of CO2, but I was wondering, let's say, on a summer day (noon), in the equatorial region, could a person actually maybe take a couple of breaths. It would be average 55 degrees temperature, so if there is ANY O2, even in the smallest amounts, you should be able to at least take a couple breaths of the martian air before feeling like you were breathing into an infinite brown paper bag. What do you think?? - Al - *----------------------------------------------------------------------* | Albert Viall | HEADLINES | | INTERNET: al@questar.QUESTAR.MN.ORG | "Dan Quayle's face seen on | | UUCP: ..!amdahl!tcnet!questar!al | Mars! It has a puzzled look!" | | FIDONET: 1/242:1,2 | "It's not for the squeemish" | |----------------------------------------------------------------------| | "Uhh, Excuse me while I take a moment to adjust my tribble." | *----------------------------------------------------------------------* ------------------------------ From: henry@utzoo.uucp To: cs.cmu.edu!space-tech@cs.toronto.edu Subject: Re: Martian Atmosphere Date: Sun, 8 Oct 89 04:08:00 EDT > Having to do with the martian atmosphere; what is it's chemical makeup, > such as percent of CO2 and other elements. And, if the is ANY O2, how much? > ...on a summer day (noon), in the equatorial region, could a person > actually maybe take a couple of breaths... There is no oxygen; zero. And if it were 100% oxygen, that still wouldn't help, because the pressure is so low that it's vacuum for all practical purposes. Surface pressure is only about 1% of Earth's. You couldn't take any breaths at all; for human purposes, there is nothing there to breathe. You need a spacesuit. Henry Spencer at U of Toronto Zoology uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: Tue, 10 Oct 89 14:03:00 EDT From: dietz@cs.rochester.edu To: henry@zoo.toronto.edu Cc: space-tech@CS.CMU.EDU Subject: Re: Martian Atmosphere Henry Spencer wrote: > There is no oxygen [in the Martian atmosphere]; zero. Not quite right, Henry. Viking measuremens found the Martian atmosphere was 0.13% oxygen. Carbon dioxide is dissociated to carbon monoxide and oxygen under UV irradiation; hydroxyl radicals from dissociated water are thought to oxidize the monoxide back to CO2. Paul F. Dietz dietz@cs.rochester.edu ------------------------------ From: henry@utzoo.uucp To: cs.rochester.edu!dietz@cs.toronto.edu Cc: cs.cmu.edu!space-tech@cs.toronto.edu Subject: Re: Martian Atmosphere Date: Tue, 10 Oct 89 14:57:00 EDT > > There is no oxygen [in the Martian atmosphere]; zero. > > Not quite right, Henry. Viking measuremens found the Martian > atmosphere was 0.13% oxygen... To almost-exactly quote one of Heinlein's characters: "So for a tenth of one percent you would make me a liar?" :-) Henry Spencer at U of Toronto Zoology uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: Wed, 11 Oct 89 16:28 EET From: Tero Siili Subject: Re: Martian Atmosphere To: space-tech@CS.CMU.EDU X-Vms-To: IN%"space-tech@cs.cmu.edu" The composition of the Martian atmosphere according to Michael E. Carr, The Surface of Mars (Yale University Press, 1981): Carbon dioxide (CO2) 95.32% Nitrogen (N2) 2.7% Argon (Ar) 1.6% Oxygen (O2) 0.13% (>0, Henry!!!) Carbon monoxide (CO) 0.07% Water vapour (H2O) 0.03% Neon (Ne) 2.5 ppm Krypton (Kr) 0.3 ppm Xenon (Xe) 0.08 ppm Ozone (O3) 0.03 ppm. Tero Siili Finnish Metetorological Institute / GEO siili@csc.fi ------------------------------ Date: Wed, 11 Oct 89 12:23 CDT From: SISKMP%VUCTRVAX.BITNET@VMA.CC.CMU.EDU Subject: Mars To: space-tech@CS.CMU.EDU X-Original-To: space-tech@cs.cmu.edu I heard somewhere that the red coloration of Mars' surface was due to iron oxide. My questions are: a) is this true b) is .13% O2 sufficient for ongoing oxidation, or is there just a lot of oxygen trapped in the Martian soil c) would this iron oxide be present on the surface, or does it make up a significant amout of the Martian rocks and soil d) Assuming a base of operations, would it be practical to mine this oxygen and iron I'm no expert, obviously. I was kind of curious as to how much the composition of the Martian atmosphere would change if (assuming significant amounts) this trapped oxygen were released. Does anyone think that it may have been free at one time? Thanks for any responses. Matt Sisk SISKMP@VUCTRVAX.BITNET ------------------------------ Date: Thu, 12 Oct 89 09:35 EET From: Tero Siili Subject: RE: Mars To: space-tech@CS.CMU.EDU X-Vms-To: IN%"space-tech@cs.cmu.edu" Matt Sisk writes: >I heard somewhere that the red coloration of Mars' surface was due to iron >oxide. My questions are: > >a) is this true >b) is .13% O2 sufficient for ongoing oxidation, or is there just a lot of > oxygen trapped in the Martian soil >c) would this iron oxide be present on the surface, or does it make up a > significant amout of the Martian rocks and soil >d) Assuming a base of operations, would it be practical to mine this oxygen and > iron The colour is indeed due to iron oxides. If you could estimate the depth of the oxidized layer and assuming a chemical composition (say, Fe2O3), you could estimate the amount of oxygen bound into the soil. If I am not mistaken, the reason for the oxygen being in the iron oxides is, that if you have iron and oxygen, it is energetically favourable for them to form oxides. Therefore, if you have pure Fe and O2 in the atmosphere, the oxygen will eventually be trapped into the soil due to chemical reactions. Somewhat analogous process is the reaction between Calcium and carbon dioxide forming carbonaceous rocks. Note, that the time it takes for the"excess" oxygen to be bound chemically certainly depends on the structure of the Fe soil, its porousness etc. It might be practical to use this source for iron, but you would need some chemical to reduce the oxides, very much the same way as on Earth. If oxygen would be the preferred end product, it might be easier to compress Martian atmosphere and distill the oxygen out. The primary advantage of that approach is, that no mining of solid substances is required. By the way, the British Interplanetary Society published last spring a special issue of their Journal, titled The Exploration of Mars. The issue contains papers on Martian resource utilization as well. You might find the issue in a library or order it from The British Interplanetary Society 27/29 South Lambeth Road London SW8 1SZ England The price for non-members is probably USD 24.00 and USD 8.00 for members. Tero Siili Finnish Meteorological Institute / Dep. of Geophysics siili@csc.fi siili@finfun.bitnet ------------------------------ Date: Thu, 12 Oct 89 13:38:42 EDT From: John Roberts Disclaimer: Opinions expressed are those of the sender and do not reflect NIST policy or agreement. To: space-tech@CS.CMU.EDU Subject: Re: the sands of Mars >From: Tero Siili >Matt Sisk writes: >>I heard somewhere that the red coloration of Mars' surface was due to iron >>oxide. My questions are: ... >The colour is indeed due to iron oxides. If you could estimate the depth of >the oxidized layer and assuming a chemical composition (say, Fe2O3), you >could estimate the amount of oxygen bound into the soil. If Mars is similar to the Earth, most of its volume is made up of oxygen- containing minerals. In other words, the availability of oxygen is not a problem on Mars (or the moon), even ignoring supplies in the atmosphere and in ice. Extraction cost must be considered, of course. I suspect that as on Earth, the majority of the mineral mass is in oxides of silicon, aluminum, etc., with iron oxide being more noticeable because of its intense color. I believe that even the "red dirt" (clay) found in Georgia and elsewhere contains only a small percentage of iron. >If I am not mistaken, >the reason for the oxygen being in the iron oxides is, that if you have iron >and oxygen, it is energetically favourable for them to form oxides. Therefore, >if you have pure Fe and O2 in the atmosphere, the oxygen will eventually be >trapped into the soil due to chemical reactions. Most of this oxidation may have taken place at a time when liquid water was present on Mars, or when the planet was originally forming. I think that on Earth, oxidation of iron is also speeded up by the presence of certain bacteria. John Roberts roberts@cmr.ncsl.nist.gov ------------------------------ From: henry@utzoo.uucp To: cs.cmu.edu!space-tech@cs.toronto.edu Subject: oxygen on Mars Date: Thu, 12 Oct 89 13:45:42 EDT > ... If I am not mistaken, > the reason for the oxygen being in the iron oxides is, that if you have iron > and oxygen, it is energetically favourable for them to form oxides. Therefore, > if you have pure Fe and O2 in the atmosphere... More to the point, if you have oxygen in the primal nebula from which the planet condensed, it will probably be found as oxides, not as pure oxygen. I doubt that Mars's surface started out as pure Fe and oxidized in place, using atmospheric oxygen; it was already oxidized when it formed, like the surfaces of Earth and the Moon. Oxygen is (for quite fundamental reasons) one of the most common elements. Most rock is something like half oxygen by weight. > It might be practical to use this source for iron, but you would need some > chemical to reduce the oxides, very much the same way as on Earth... Probably the simplest approach would be to react it with hydrogen and electrolyze the resulting water (which gives you back the hydrogen to use again). > If oxygen > would be the preferred end product, it might be easier to compress Martian > atmosphere and distill the oxygen out. The primary advantage of that > approach is, that no mining of solid substances is required. Possibly a much better way to get oxygen, though, is to reduce the carbon dioxide in the atmosphere. This likewise does not require mining, and there is several hundred times as much CO2 in a given volume of Martian air. If you're using chemical reduction (as opposed to photosynthesis), you get carbon monoxide as a byproduct, which is relevant because it's a practical (although unimpressive) rocket fuel. Henry Spencer at U of Toronto Zoology uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ End of Space-tech Digest #39 *******************