Author Topic: EPA Now Looking at Shuttle SRB Perchlorate Oxidizer--again...  (Read 16798 times)

Offline iamlucky13

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....if perchlorate from SRM exhaust grounds vehicles using solids the Air Force can rely on Delta IV-Heavy for assured access to space...

There are not significant perchlorates in SRB exhaust. The major components are  water, carbon dioxide, hydrogen chloride, and a metal oxide (typically aluminium oxide): http://en.wikipedia.org/wiki/APCP

The source of perchlorate contamination is being researched. Vast amounts of perchlorates were used in certain agricultural fertilizers.  Only recently has technology existed to detect perchlorate contamination at low levels.

The relationship (if any) between solid rocket fuel and perchlorate contamination is in the manufacturing phase, not the usage phase.

Ammonium perchlorate propellant used in human spaceflight does produce HCl (Hydrogen chloride), but the quantity is insignificant relative to coal-fired power plants and waste incineration.

Solid propellant obviously has some environmental impact, but economic and engineering factors limit the flight rate, hence overall impact. Solid fuel is simply not scalable to extremely high flight rates, but has certain advantages at lower flight rates.

Concerns about environmental impact at high flight rates which are unachievable from an economic and engineering standpoint seem misplaced.

Be careful where you post that. Around here, where substantive analysis is welcomed, you'll get away with it. If you try to to tell this to hardcore greenies who are offended by technological achievements, you're likely to be tarred and feathered. When those folks find a technical sounding term to latch onto and demonize like perchlorate, they'll be darned if they'll bow to practical considerations like what actually ends up in the environment. For further reference, see the discussion of mercury in fluorescent lightbulbs.

Anyway, you beat me to it. At one point I actually broke down the amount of each chemical produced by the SRB's in appropriate ratio, and compared to natural or industrial occurrence of it. Unfortunately, I didn't save my figures (I need to start doing that more often) The HCl is the most concerning product, but SRB's account for a tiny fraction of worldwide HCl release, and it breaks down fairly readily in UV light. The earth's chlorine cycle is fairly active.

Subject: 4.5) Space shuttles put a lot of chlorine into the stratosphere.
Simply false.

Simply math:

725t * 100% / (0.3 * 1,000,000t + 75,000t) = 0.193%

There's a bunch of different numbers bouncing around here, but note that 1 Mt is for CFC's. Another source Joema posted cites 8 Mt of industrial HCl per year. Also, one states 1/3 of shuttle exhausted HCl makes it to the stratosphere

So:

725t * 0.33 / (0.3 * 8,000,000t + 75,000t) * 100% ~= 0.01%

That's an order of magnitude off from your number, but then again, your number is already three orders of magnitude smaller than the global HCl emissions. If we're assuming a linear relationship between concentration and activity, a 0.1% much less an 0.01% increase in concentration are going to have a generally negligible effect. That's not necessarily an accurate assumption, but in lieu of any other information about the effect of chlorine on ozone, it seems fair.

Offline madscientist197

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So:

725t * 0.33 / (0.3 * 8,000,000t + 75,000t) * 100% ~= 0.01%

That's an order of magnitude off from your number, but then again, your number is already three orders of magnitude smaller than the global HCl emissions. If we're assuming a linear relationship between concentration and activity, a 0.1% much less an 0.01% increase in concentration are going to have a generally negligible effect.

Wrong in multiple ways:
1. You didn't read Joema's post properly! 725t was the amount that actually reaches the stratosphere.
2. You didn't read my post properly. What's up with the 0.3 multiplier in your equation? In my case it was from 0.3Mt (no -- not millitesla ;), megatons)
3. Your assumptions about industrial emissions are bogus -- I'll give you a quote from the EPA website
http://www.epa.gov/Ozone/science/sc_fact.html
Quote
Chlorine from swimming pools, industrial plants, sea salt, and volcanoes does not reach the stratosphere. Chlorine compounds from these sources readily combine with water and repeated measurements show that they rain out of the troposphere very quickly. In contrast, CFCs are very stable and do not dissolve in rain. Thus, there are no natural processes that remove the CFCs from the lower atmosphere. Over time, winds drive the CFCs into the stratosphere.

So in order to have an effect Chlorine must be either:
1. Emitted *IN* the statosphere (hence shuttle) or
2. Emitted in an unreactive form like CFCs, that can eventually reach the stratosphere and break down.

So you can take those industrial emissions of Chlorine and multiply them by 0 (or thereabouts):
725t / (0 * 8,000,000t + 300,000 + 75,000t) * 100% ~= 0.19%

Quote
That's not necessarily an accurate assumption, but in lieu of any other information about the effect of chlorine on ozone, it seems fair.

Maybe not. ;)

Be careful where you post that. Around here, where substantive analysis is welcomed, you'll get away with it. If you try to to tell this to hardcore greenies who are offended by technological achievements, you're likely to be tarred and feathered. When those folks find a technical sounding term to latch onto and demonize like perchlorate, they'll be darned if they'll bow to practical considerations like what actually ends up in the environment. For further reference, see the discussion of mercury in fluorescent lightbulbs.
There's not much you can do about irrational people. I don't see what irks people about what I'm saying though -- this isn't an environmental forum and it has rational people on it. I'm not scaremongering or arguing to get rid of the SRBs. Just that everyone seems to want to deny that the SRBs have any effect on the ozone layer when they clearly do. Do I care whether they damage the ozone layer? No. But others will eventually club NASA over the head with it.
« Last Edit: 08/27/2009 02:09 am by madscientist197 »
John

Offline iamlucky13

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Wrong in multiple ways:
1. You didn't read Joema's post properly! 725t was the amount that actually reaches the stratosphere.
2. You didn't read my post properly. What's up with the 0.3 multiplier in your equation? In my case it was from 0.3Mt (no -- not millitesla ;), megatons)
3. Your assumptions about industrial emissions are bogus -- I'll give you a quote from the EPA website
http://www.epa.gov/Ozone/science/sc_fact.html
Quote
Chlorine from swimming pools, industrial plants, sea salt, and volcanoes does not reach the stratosphere. Chlorine compounds from these sources readily combine with water and repeated measurements show that they rain out of the troposphere very quickly. In contrast, CFCs are very stable and do not dissolve in rain. Thus, there are no natural processes that remove the CFCs from the lower atmosphere. Over time, winds drive the CFCs into the stratosphere.

So in order to have an effect Chlorine must be either:
1. Emitted *IN* the statosphere (hence shuttle) or
2. Emitted in an unreactive form like CFCs, that can eventually reach the stratosphere and break down.

So you can take those industrial emissions of Chlorine and multiply them by 0 (or thereabouts):
725t / (0 * 8,000,000t + 300,000 + 75,000t) * 100% ~= 0.19%

You're right. I did read it wrong. I guess I was trying to tie together too many data sources without writing anything down. I was assuming the same 30% of the 8 Mt of emitted HCl as CFC's reaches the stratosphere.

However, I stand by my final argument in lieu of further information.

And to be clear, I'm not slamming you by any means. The biting part of my post was at those would potentially "club NASA over the head" with this stuff.

Offline sdsds

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This just in:

Nitrous oxide fingered as monster ozone slayer

By Janet Raloff

"N2O is no laughing matter. New calculations indicate that it has risen to become the leading threat to the future integrity of stratospheric ozone."

http://www.sciencenews.org/view/generic/id/46776/title/Nitrous_oxide_fingered_as_monster_ozone_slayer
-- sdsds --

Offline khallow

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Another thing to consider is that even in our enlightened legal system, someone will need to demonstrate considerable harm before SRBs can be banned. I really don't think there's much to worry about. If SRBs get banned, then it's likely that any rocket technology will be extremely vulnerable to banning. Even LOX/LH2 generates nitrogen oxides (the exhaust isn't room temperature, you know) and injects the notorious compound, dihydrogen monoxide into our precious ozone layer.
Karl Hallowell

Offline deltaV

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injects the notorious compound, dihydrogen monoxide into our precious ozone layer.
Worse yet dihydrogen monoxide is a major greenhouse gas.  ;)

Offline Warren Platts

OK, so mad-sci says that SRB's are responsible for 0.2% of the chlorine. And someone else says the ESA's rockets are putting in a comparable amount. So that makes roughly ~0.4%. And that's at today's paltry, primitive space program.

Now, would even a two-order magnitude increase over current launch rates qualify as "routine" orbital access? Well, I suppose, we could say that the current program is routine. Fine. Still, don't we, shouldn't we, can't we(?) want more???

Is a Shuttle-flight-equivalent-a-day too much to ever ask for? That doesn't seem like much, yet that is a two-order-of-magnitude boost over today's launch rates. Is that more than we can aspire to--IN THIS GENERATION?

If not, then if we don't change our technology, then there will be a huge boost in total stratospheric chlorine inputs, and then SRB's will account for a good 30% of the total. And what if there are ten Shuttle-flights-equivalent per day? At that point, SRB's are the world's largest stratospheric polluters by far. And that's only 10 flights per day--globally. 10 flights a day is not exactly O'Hare Airport numbers.

Don't you see? If you say that the pollution from SRB's is of no concern because: (a) the total amount isn't much compared to the TOTAL amount [which of course doesn't address why NASA as an incremental point source ought to be given a pass, when my right to use CFC underarm spray is regulated]; and (b) it will be so long before spaceflight will become common enough that there is no need to design green rockets for the foreseeable future.

That my friends, is a councel of despair.

I was a fence-sitter when it came to Ares and Constellation--with me leaning towards the status quo, because even if it wasn't the best plan, it was at least a plan. Now, after considering the environmental impacts of a robust launch schedule that would be required for serious HSF, I say that's the straw that breaks the camel's back in my mind. It's a debateable program at best--and yet it's funny that the detractors are now saying that Cxn's dirtiness isn't any concern. Whoever said their isn't honor amongst thieves?

In addition, as a fellow space enthusiast, I advise that politically, it would be best to avoid the psuedo-cowboy, anti-environmentalism. Hubris never plays well in democracies. And I call the macho, dirty posturing "psuedo-cowboy", because real cowboys play to win, and they are not anti-environment. They CARE about the environment, because they have to because they make their livings off the environment--as we all do, ultimately, after all, right?
« Last Edit: 08/28/2009 04:32 am by Warren Platts »
"When once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return."--Leonardo Da Vinci

Offline madscientist197

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I don't see SRB exhaust ever being a serious consideration, because I don't think SRBs are considered seriously for high flight rate regimes. When you get to the point of 10 flights a day it will be be using different technology from what we currently have today. Possibly something along the lines of LOX/Biofuel thrust augmented NH4/Nuclear (informed speculation at best). There would be all sorts of pad corrosion issues and severe local ecological damage caused by launching solids every day. IMHO anyone who does that deserves to be strung up by a crowd of environmentalists ;p
« Last Edit: 08/28/2009 10:51 am by madscientist197 »
John

Offline Jorge

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I agree with madscientist. All this means is that SRBs are unsuitable for high-flight-rate systems, but everybody with a lick of sense knew that already.
JRF

Offline Warren Platts

Quote from: Jorge
I agree with madscientist. All this means is that SRBs are unsuitable for high-flight-rate systems, but everybody with a lick of sense knew that already.
I guess I must not have a lick of sense, because I'm confused. The Space Shuttle was originally designed under the premise that the program could deliver one manned flight per week. Indeed, the hope was to be able to turn each orbiter around in two weeks. With four orbiters, that would be ~100 flights per year. The idea is that the average cost per flight would be low because of amortization. That proved impractical, of course--but apparently, the environmental effects of such a high launch rate were not a consideration.

So what's the deal? A high launch rate was desirable in the 1970's, but not in the 2020's????

So I ask you, Jorge, if SRB's are not suitable for high launch rates, then why in hell are we not only still using them, but are incorporating them into our new designs? It's a set up for failure. THat's what I think anybody with a lick of sense would see.
"When once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return."--Leonardo Da Vinci

Offline Jorge

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Quote from: Jorge
I agree with madscientist. All this means is that SRBs are unsuitable for high-flight-rate systems, but everybody with a lick of sense knew that already.
I guess I must not have a lick of sense, because I'm confused. The Space Shuttle was originally designed under the premise that the program could deliver one manned flight per week. Indeed, the hope was to be able to turn each orbiter around in two weeks. With four orbiters, that would be ~100 flights per year. The idea is that the average cost per flight would be low because of amortization. That proved impractical, of course--but apparently, the environmental effects of such a high launch rate were not a consideration.

So what's the deal? A high launch rate was desirable in the 1970's, but not in the 2020's????

Correct. That was a false "lesson learned" from the failure of the space shuttle to achieve the original flight rate.

Quote
So I ask you, Jorge, if SRB's are not suitable for high launch rates, then why in hell are we not only still using them, but are incorporating them into our new designs?

Because the space shuttle is now acknowledged not to be a high-flight-rate system, as are the systems proposed to replace it. NASA has given up on the concept of high flight rates.
JRF

Offline madscientist197

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So I ask you, Jorge, if SRB's are not suitable for high launch rates, then why in hell are we not only still using them, but are incorporating them into our new designs? It's a set up for failure. THat's what I think anybody with a lick of sense would see.
It's a very good question.... I don't have a particularly good answer.
John

Offline docmordrid

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The EPA just issued orders for their drones write new regulations on perchlorates. 

Doesn't sound like good news for ATK or "shuttle derived" HLV's.

NY Times....
« Last Edit: 02/03/2011 02:49 am by docmordrid »
DM

Offline M_Puckett

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For municipal drinking water systems, not for non-point sources like SRBs.

Google EPA public drinking water standards for more info what this is about.  They are just adding a standard method for analysis and an MDL for Perchlorate for post-treatment drinking water.

According to the article, they haven't even set a standard yet.  Untill someone does acute and chronic tox testing and publishes the results, this is all meaningless anyways.

Offline docmordrid

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Read the article - esp paragraphs 6-8.  It notes the source of perchlorate contaminated round water as the impetus and military & rocket testing as problem areas. 

400 problem locations, and you can bet your bippy production and use facilities and surrounds are at the top of the list. 

How do they not affect NASA's use of large solids once the regs hit, and with Obama having to re-certify himself among liberals after the tax bill how long before EPA acts?  I bet not long.  This EPA is more dogmatic than before.
« Last Edit: 02/03/2011 03:14 am by docmordrid »
DM

Offline M_Puckett

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Again, unless NASA is operating a public drinking water plant in a contaminated aquifer, this is irrelevant.  39A and B are on salt-water aquifers hydraulically connected to the atlantic anyways.  No potential for drinking water contamination.

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