Submitted by marketrent t3_10ufb9b in science
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Findings in title quoted from the linked summary^1 and its hyperlinked journal paper T. Brown, et al.^2
From the 3 Feb. 2023 summary^1 by the authors of T. Brown, et al.:
>Rockets have exciting potential to enable industrial-level access to near-Earth space and exploration throughout the solar system.
>This makes them “charismatic technology” – and the promise of what the technology can enable drives deep emotional investment.
>The allure of possibility can get in the way of even discussing how to make rockets achieve these aspirational goals without damage. We have to be able to have clear discussions.
>The ozone layer is on track to heal within four decades, according to a recent UN report, but this progress could be undone by an upsurge in rocket launches expected during the same period.
>As we show in our new review, the gases and particulates rockets emit as they punch through the atmosphere could lead to delays in the ozone layer’s recovery.
>Fortunately, the number of launches to date is so small that the impacts on the ozone layer are currently insignificant.
>However, over coming decades the launch industry is set to expand considerably.
>
>As we outline, rocket emissions in the upper atmosphere can affect the ozone layer but are not regulated. We argue this policy gap must be filled to ensure sustainable growth of the rocket launch industry and protection of the ozone layer.
>The launch industry today relies on four major fuel types for rocket propulsion: liquid kerosene, cryogenic, hypergolic and solid.
>The combustion of these fuels means contemporary rockets create a suite of gaseous and particulate exhaust products, including carbon dioxide, water vapour, black carbon, alumina, reactive chloride and nitrogen oxides. These products are known to destroy ozone.
>A new fuel is methane, which is used in multiple rocket engines under development by major launch companies. The emissions products of methane are as yet poorly understood.
>In the stratosphere, an upper level of the atmosphere where the protective ozone layer resides, emissions linger for much longer than lower down.
>Small amounts of an exhaust byproduct can have greater destructive effects in the upper atmosphere than when close to Earth’s surface.
^1 Rocket industry could undo decades of work to save the ozone layer, 3 Feb. 2023, https://www.canterbury.ac.nz/news/2023/rocket-industry-could-undo-decades-of-work-to-save-the-ozone-layer.html
^2 T. Brown, M. Bannister, and L. Revell. Envisioning a sustainable future for space launches: a review of current research and policy. Journal of the Royal Society of New Zealand 2023. https://doi.org/10.1080/03036758.2022.2152467
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That's what I've been saying since the Space Shuttle was developed.
Uh am I just blind, or is there no actual data here, just some dudes waving their hands and hypothesizing stuff they think is plausible?
And that hypothesis, even, is especially un-compelling IMO when they include hypergolic propellants in the list: that is the source of most of the super toxic shit BUT is also definitely not the propellant being used in the vast majority of those extra 100 launches.
Hypergolics are used for military rockets mostly where stable storage for years is the main concern. Commercial launches use almost entirely vastly cleaner RP-1 refined kerosene, hydrogen, or methane fuels
Angry luddites against the final frontier
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> A new fuel is methane, which is used in multiple rocket engines under development by major launch companies. The emissions products of methane are as yet poorly understood.
????? What? The combustion byproducts of a methalox rocket is mostly H2O and CO2.
And it isn’t poorly characterized. The report authors just don’t look into it. NASA has a wonderful piece of software/web site that you can run Computational Chemical Equilibrium simulations, even simulated rocket engines. And it is pretty accurate.
And for a 300 bar , sea level methalox engine it spits out the following mass fractions of various species at the Comustion Chamber, the throat, and most importantly for this discussion the Exit. (Forgive the formatting, on mobile)
Species. Chamber Throat Exit
*CO 0.22048 0.20984 0.13790
*CO2 0.27689 0.29368 0.40681
COOH 0.00009 0.00005 0.00000
*H 0.00071 0.00060 0.00001
HCO 0.00004 0.00002 0.00000
HO2 0.00028 0.00016 0.00000
*H2 0.00681 0.00644 0.00695
HCOOH 0.00002 0.00001 0.00000
H2O 0.41879 0.42748 0.44829
H2O2 0.00008 0.00004 0.00000
*O 0.00481 0.00356 0.00000
*OH 0.04585 0.03779 0.00005
*O2 0.02515 0.02032 0.00000
So as you can see, the vast majority of the exhaust is Water, Carbon Dioxide, and Carbon Monoxide. Now there will be other trace components because the system assumes the LOX and Methane are totally pure, but even then those will be trace.
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Well this certainly makes Grimes being quoted saying "Elons son will have to fight in the climate wars" slightly more ironic.
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crimeoPhD
>Uh am I just blind, or is there no actual data here, just some dudes waving their hands and hypothesizing stuff they think is plausible?
>And that hypothesis, even, is especially un-compelling IMO when they include hypergolic propellants in the list: that is the source of most of the super toxic shit BUT is also definitely not the propellant being used in the vast majority of those extra 100 launches.
>Hypergolics are used for military rockets mostly where stable storage for years is the main concern. Commercial launches use almost entirely vastly cleaner RP-1 refined kerosene, hydrogen, or methane fuels
The authors are “just some dudes” whose review of research and policy is peer-reviewed.
The lexicon for describing peer-reviewed hypothesis — could or plausible included — may be unfamiliar to audiences accustomed to assertions of opinion.
I can't help but notice that you didn't answer the question
> Am I just blind, or is there no actual data here?
Where is the data? WHAT was reviewed by their peers? They haven't actually gone out and done or measured anything to be reviewed, unless I'm missing it in the article. Hence the "am I just blind?" because I was confused how this would be published if so and am doubting myself. The blind part is an honest question
>crimeoPhD
>I can't help but notice that you didn't answer the question
>>Am I just blind, or is there no actual data here?
>Where is the data? WHAT was reviewed by their peers? They haven't actually gone out and done or measured anything to be reviewed, unless I'm missing it in the article.
Findings in title are quoted from the linked summary^1 and its hyperlinked journal paper T. Brown, et al.^2 as cited in my excerpt comment.^3
Perhaps correspondence with the authors — environmental physicist Laura Revell, planetary scientist Michele Bannister, and first author Tyler Brown — may be productive.
^1 Rocket industry could undo decades of work to save the ozone layer, 3 Feb. 2023, https://www.canterbury.ac.nz/news/2023/rocket-industry-could-undo-decades-of-work-to-save-the-ozone-layer.html
^2 T. Brown, M. Bannister, and L. Revell. Envisioning a sustainable future for space launches: a review of current research and policy. Journal of the Royal Society of New Zealand 2023. https://doi.org/10.1080/03036758.2022.2152467
> Findings in title are quoted from the linked summary
Yes I know the actual (journal) article was linked, as in the doi.org one by the royal society of new zealand. I looked over that and was already referring to the actual article. But what data did it add to the story? My summary of what I read is roughly:
We counted that there's more launches than before.
Launches in general have these handful of chemicals. The relative proportions of which are unspecified, either in whole OR by launch type.
How many of each launch type there were before or among the newly added launches is also... unspecified.
How badly each chemical affects the ozone layer is unspecified. We gave a reaction written out of what could happen with regard to ozone, but not how much this actually happens in practice (e.g. after accounting for other side reactions using up that chemical for other products first, before it gets to ozone).
But it could be really bad! Maybe. If all those unspecified numbers turned out to be bad.
In summary: An unspecified mixture of types of new launches adds unspecified amounts of chemicals per type, and unspecified amounts overall, with an unspecified effect of each on the ozone layer... did I get that right?
> Perhaps correspondence with the authors — environmental physicist Laura Revell, planetary scientist Michele Bannister, and first author Tyler Brown — may be productive.
It's a reddit thread, it is a forum for quick discussion about what's presented already, not weeks long correspondence that nobody will ever see the results of since the thread will be gone for weeks by then itself.
>crimeo
>It's a reddit thread, it is a forum for quick discussion about what's presented already, not weeks long correspondence that nobody will ever see the results of since the thread will be gone for weeks by then itself.
For veracity, you may wish to send a facsimile of your comments to the authors, as “quick discussion” by subreddit users other than authors could invite inaccuracies.
If you think reddit is not an appropriate forum, why did you, the OP, post this thread to reddit...?
Insert looks of surprise and shock here.
As you have shown the percentages can you also give us a link to the mass of the fuel reflected in these percentages. I think that would help in quantifying the amount of admission being dumped into the different layers of our atmosphere.
Each launch is roughly the equivalent of a 747's worth of fuel (kerosene or methane).
Sounds like someone needs construct a Space Elevator.
Backyard astronomers start foaming at the mouth
Sigh.
Jet Engines repopulate the upper layers. They spray 'em, the atmosphere schmears 'em.
The proper fuels matter of course, but I'm sure someone will figure that out if they haven't already.
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>rocket emissions in the upper atmosphere can affect the ozone layer
What primary research shows that? By how much was the ozone layer affected?
I thought one isn't supposed to post reviews here. I'm under the impression this forum is here to discuss primary research where the methods are open and revealed.
About 650 kg/s for the inputs according to Wikipedia. 510 kg/s of LOX and 140 kg/s of CH4 for a Raptor engine.
But it really depends on the engine in question and the throttle level.
Right when the magnetic field is weakening too
They would have to be incredibly lucky and against almost all common sense that massive rooms of rock could get exhausted you know don't have a negative impact.
Typically when you mind chemicals on Earth and then Mass release them in almost any form it has a negative consequence.
Kind of like Earth is a big ball of unregulated chemical reaction and when you throw yet more non-naturally occurring chemicals into that biosphere of chemicals generally bad s*** happens.
Pattern has repeated so many times throughout human history that it's almost like you have to be in denial of science to come to that conclusion even without significant study.
The very least it's some massive wishful thinking to think that the rocket pollution is harmless enough just like humans thought CO2 was harmless enough or let it gasoline was harmless enough and looking back at it those were very dumb assumptions.
Need space elevator now please.
"Let's just go on common sense and off the cuff assumptions instead of measuring anything"
Why are you on a subreddit called /r/science if you don't think science is necessary, bro?
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