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Author
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Topic: Commercial spaceflight effects on the atmosphere
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SkyMan1958
Member Posts: 867
From: CA.
Registered: Jan 2011
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posted 06-28-2011 02:14 AM
   
First off, I would LOVE to fly into space. Having said that, it does seem logical to me that the more people fly into space the more we will degrade the upper reaches of the atmosphere. The (US) supersonic transport (SST) got canceled because of concerns of degradation of the ozone layer courtesy of the NOx's spewed by the plane. Because of that (and concerns about sonic booms) the US only allowed SSTs to fly to New York and D.C., which essentially destroyed the commercial viability of SSTs. Clearly the rockets we send into space create a bunch of NOx's along the way (along with a grab bag of other pollutants), and the more rockets we send the more NOx's and other pollutants will be created/spewed into the upper atmosphere. Do you think this will put a serious crimp in commercializing space? Do you think it should? |
gliderpilotuk
Member Posts: 3398
From: London, UK
Registered: Feb 2002
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posted 06-28-2011 07:15 AM
quote:
Originally posted by SkyMan1958:
The (US) supersonic transport (SST) got canceled because of concerns of degradation of the ozone layer courtesy of the NOx's spewed by the plane.
Nah, that was just a 70's pre-climate-change conspiracy theory.  |
Byeman
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posted 06-28-2011 07:18 AM
quote:
Originally posted by SkyMan1958:
Clearly the rockets we send into space create a bunch of NOx's along the way (along with a grab bag of other pollutants), and the more rockets we send the more NOx's and other pollutants will be created/spewed into the upper atmosphere.
Clearly? Not so. The SST engines ingested nitrogen and NOx were formed in the burners. It is not the same conditions with liquid engines. |
Spaceguy5
Member Posts: 427
From: Pampa, TX, US
Registered: May 2011
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posted 06-28-2011 07:21 AM
Liquid engines using LOX and LH2 just produce water. |
SpaceAholic
Member Posts: 4437
From: Sierra Vista, Arizona
Registered: Nov 1999
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posted 06-28-2011 07:36 AM
Methane has improved performance over LH2 (less so then RP1) and is just as environmentally friendly. |
Ross
Member Posts: 472
From: Australia
Registered: Jul 2003
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posted 06-28-2011 08:29 AM
Unfortunately the only rockets that are 'clean' are liquid O2/liquid H2. All others produce pollutants to one degree or another. For example, SRBs produce various pollutants and methane is not environmently friendly. It produces CO and CO2. While this doesn't effect the Ozone layer, in large enough amounts it effects climate. Certainly not a problem at present or in the near future. But one needs to do calculations to determine what the effect of the daily launch of rockets in the medium term would be.A bigger problem may be the amount of debris left in orbit. Strict rules must be enforced to prevent this becoming an even bigger problem than today. |
SkyMan1958
Member Posts: 867
From: CA.
Registered: Jan 2011
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posted 06-28-2011 01:28 PM
Folks, let me give you a VERY basic chemical lesson. The fuel burned is not what produces the NOx's. It is the high heat of combustion that produces the NOx's. Nitrogen in the atmosphere is generally in the form of N2. When high heat is produced, the bonds between the two atoms are broken and you have two N atoms floating around. If they then combine with free O you get NOx's. So, within reason, the creation of the NOx's is NOT a function of the type fuel consumed, it is a function of the heat produced by high temperature combustion in the atmosphere. So, the more rockets flying through the stratosphere, the more NOx's that will be produced in the stratosphere, and the higher the degradation of the ozone layer. |
Byeman
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posted 06-28-2011 02:06 PM
quote:
Originally posted by SkyMan1958:
Folks, let me give you a VERY basic chemical lesson. Basically, the fuel burned is not what produces the NOx's. It is the high heat of combustion that produces the NOx's.
Let me give a VERY VERY basic lesson on jet and rocket engines. When a jet ingests atmosphere N2 and it passes through the burners where the atmospheric oxygen mixes with fuel and creates the high heat of combustion produces the NOx's. The same mechanism does not exist with rockets. Yes, a little N2 is exposes to the exterior of flame but many magnitudes less and for much less time. the vehicles leave the sensible atmosphere in less than 5 minutes. |
SpaceAholic
Member Posts: 4437
From: Sierra Vista, Arizona
Registered: Nov 1999
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posted 06-28-2011 02:20 PM
The effects of chemical propulsion exhaust plume kinetics are local and transitory (thanks to upper atmospheric mixing)... no persistence, no issue - model launch rate, launch vehicle performance, configuration and plume characteristics, local upper atmospheric weather and wind sheer, etc.) and I bet in the grand scheme of things there will be negligible impact (a small fraction of that produced by the commercial aviation industry).
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Ross
Member Posts: 472
From: Australia
Registered: Jul 2003
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posted 06-29-2011 09:07 AM
Sorry Byeman, but your statement that the type of fuel doesn't matter is incorrect. As I mentioned in my previous message SRBs do produce pollutants including NOxs and it has little to do with the N2 in the atmosphere. The fuel itself contains nitrogen atoms which when burnt produces small quantities of NOxs, not to mention HCl and chlorine. There are also some liquid fuels, although not used for the Space Shuttle for example, that contain nitrogen and thus produce NOxs.However, as pointed out by SpaceAholic the total effects are small compared to the aviation industry. |
Byeman
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posted 06-29-2011 10:52 AM
quote:
Originally posted by Ross:
As I mentioned in my previous message SRBs do produce pollutants including NOxs and it has little to do with the N2 in the atmosphere.
SRB use is on the downfall and that why I excluded them.Current US liquid launch vehicles lower stages don't use propellants that include N. |
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