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Earth Space Transportation Science

Calculating Environmental Damage From Space Tourism Rockets 83

Posted by Soulskill
from the i-can-see-the-smog-around-my-house-from-here dept.
MithrandirAgain writes "A new study from several scientists at the Aerospace Corporation claims spaceships that rely on rubber-based fuel could help cause climate change. The fuel apparently expels a black carbon soot into the stratosphere when burned with nitrous oxide, which could be contributing to global climate changes, like shrinking the icecaps. However, the authors are careful about their work being an end-all study and are 'inviting others to take a look.' Virgin Galactic, whose SpaceShipTwo just made its first solo flight (and uses the type of fuel discussed in the study), is listening to the scientists' concerns. CEO George Whitesides said, 'I think we and others in the industry welcome the opportunity to talk about all of these issues.' SpaceShipTwo does use a hybrid engine 'because of its significantly lower environmental impact than other designs,' and Whitesides stresses, 'I think as we look at this more, we'll find the impact will be far smaller than that set out in the paper. In any case, I welcome the conversation.'"
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Calculating Environmental Damage From Space Tourism Rockets

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  • I'm impressed ... (Score:3, Interesting)

    by ScrewMaster (602015) * on Saturday October 30, 2010 @09:21AM (#34072602)

    However, the authors are careful about their work being an end-all study and are 'inviting others to take a look.'

    A refreshing attitude ... that's how science is supposed to work. There have been far too many bombastic claims made about global warming.

    • Re: (Score:3, Insightful)

      However, the authors are careful about their work being an end-all study and are 'inviting others to take a look.'

      A refreshing attitude ... that's how science is supposed to work.

      While I agree that researchers should encourage others to perform independent studies, I find the approach of this group to be disingenuous at best. I find this comment (in the comments to the Wired article) to be particularly insightful:

      This is close to corporate blackmail, and is symptomatic of the way climate science is abused to generate alarmist headlines. They take three flights every day for 40 years, and no doubt the assumptions about the amount of soot particles is similarly “generous,” plug in absolute worst-case numbers until they get an alarming result, and PROFIT$$$.

      The profit for them is to generate alarming headlines. You can’t afford to not pour more money into my field or the WORLD WILL END!! (please be sure to spell my name right when you mention my research) And if you are Richard Branson, we will give your company a sooty black eye unless you fund more of our research. C’mon, rich man, pay up!

      There is certainly room for sober investigation, and as environmentally conscious as Branson is, he probably would have okayed a chase plane sampling the exhaust trail. Certainly all the atmospheric science models could use vastly more data to move beyond the wild guess stage. The constant claims of impending disaster from overstated claims, though, will backfire.

    • Re: (Score:2, Interesting)

      by Anonymous Coward

      To be honest I think this study is environmental FUD. They are saying that 40,000 launches over 40 years can cause significant environmental change including 1.8 degree temperature shift (positive) at the poles.

      The obvious question that comes to my mind is why do think that any significant amount of soot from the 1000 rockets launched this year would still be in the atmosphere in 40 years? Do they have any reason to suspect that it stays around that long? The thing that comes to mind for me with

      • by damburger (981828) on Saturday October 30, 2010 @12:13PM (#34073774)

        This offends your worldview so you dismiss it.

        For a better analysis, lets review the story so far:

        1. A group of highly qualified academics publish research showing that hybrid rocket engines *may* have a polluting effect far out of proportion to the emissions they have on paper. The researchers are careful to stress the word *may*

        2. They find another expert in the field who says "This is interesting, but not a definitive conclusion" i.e. agrees with the assessment of the original team.

        3. Spokespeople for corporations who want to make profits from the use of hybrid rockets say its all bullshit, despite these spokespeople having no real qualifications.

        Then you come along with some volcano analogy, despite the fact the entire study is based on the *high altitude* generation of soot particles and I haven't seen any flying volcanos recently.

        When science says things you don't like, and you decide to dismiss the academic structures on which science is based just because you don't like the new (possible) reality, that is a bit of a dick move.

        Here is the real bitch though; nobody is going anywhere significant in N20/rubber hybrid rockets. They are good for quick-and-easy sub-orbital rides because they are safe and simple to build, but to get into orbit you need more powerful fuels which likely do not have the soot problem - so if space tourism does take off and get some non-pathetic technology, they will have moved on from producing soot-rich exhausts anyhow.

        • by ScrewMaster (602015) * on Saturday October 30, 2010 @12:37PM (#34073930)

          Then you come along with some volcano analogy, despite the fact the entire study is based on the *high altitude* generation of soot particles and I haven't seen any flying volcanos recently.

          The GP is absolutely correct though. The article was talking about stratospheric effects. As it happens, vulcanism is perfectly capable of ejecting all sorts of substances that can have profound effects on weather into the stratosphere. [usgs.gov] How do you think eruptions like Krakatoa and Pinatubo had globe-spanning effects?

        • Academics? You sure about that? This appears to be a corporation that offers sort of consultation services about launch capabilities, planning and verification they are involved in such launch programs as Atlas I and II, Centaur, Delta II, and EELV they might have an agenda. Not sure if they do but they may be crapping their pants over much cheaper alternatives to their expensive federally funded program (just saying)

      • by goodmanj (234846) on Saturday October 30, 2010 @12:35PM (#34073916)

        Careful now: FUD as we typically use it on Slashdot is doubt raised by pure rhetoric, in the absence of facts. These guys have actual *data*. You can question their assumptions, but they're not just using scary words.

        The obvious question that comes to my mind is why do think that any significant amount of soot from the 1000 rockets launched this year would still be in the atmosphere in 40 years? Do they have any reason to suspect that it stays around that long?

        I've found the original Geophysical Research Letter [agu.org] article (it's behind a paywall unless you're at an institution that subscribes to GRL, which I am).

        They do *not* assume that the soot sticks around for 40 years: they include a settling time for the soot particles of a couple of years (details more complicated). But they run the model for 40 years to give the ocean and cryosphere time to adjust.

        They use a detailed model of the interaction of sunlight with soot particles: this model was developed for studying nuclear holocaust scenarios. They make some assumptions here about the size and properties of rocket soot particles, but I don't see any red flags.

        Finally, again comparing to volcano's, the best data I can find for a volcanic eruption that changed the climate (1991 Pinatubo) suggests that it dumped 17 million tons of CO2. I know this is talking about rubber particulates and not CO2, but there's a big difference in magnitude between 17 million tons in a few days and 1.3 million tons over 40 years.

        Soot particles have a *very* different climate effect than CO2, it's apples and oranges.

        Based on what I read in their article and on my personal experience as a climate modeling scientist, I can tell you that they're using the right computer model for the job, and their assumptions about soot input seem reasonable, and they're including all the relevant physics.

        It should also be mentioned that the climate change effects they're predicting (1 polar temperature rise, 5-15% northern polar sea ice loss) are observable, but *much* smaller than the predicted changes from anthropogenic greenhouse gas emissions (up to 8C polar temperature rise, possible total loss of summer sea ice). But still, no joke.

    • by flyneye (84093)

      Yes, refreshing.
      I usually think of extreme bias crawling underneath the S(tudy) word. I usually see it batted around as propaganda to a public who doesn't know the difference between a curious sampling of data that amounts to sticking your toe in the water determining if more money should follow from rigorous actual full blown research covering every conceivable factor in order to determine proof.

      You can't turn on the television without hearing from

    • Yep. Here is my completely biased coverage on [hot topic of the day], and I make a lot of outrageous 'assumptions'. Then here is my complete FUD to make everybody 'think'.

      But then here, I am 'inviting others to take a look' so that I can get away with all the rambling and come out as fair and balanced.

    • Who cares if we wreck the planet? We're leaving.

  • by ScrewMaster (602015) * on Saturday October 30, 2010 @09:28AM (#34072612)
    What I find interesting is that they're claiming that injecting soot into the stratosphere would cause global warming (at least according to the summary, didn't RTFA.) When blasts of particulate matter from other sources have reached those heights (for example, when Krakatoa went postal) it resulted in global cooling instead. I'm assuming there's a different mechanism involved.
    • by Anonymous Coward

      A quick google query and you can figure this out for yourself.

      Volcanoes create a cooling effect due to the sulfur they spew into the high atmosphere.

      Direct sulfur injection is actually a proposed geo-engineering solution to global warming.

      http://www.livescience.com/environment/060727_inject_sulfur.html

    • Re: (Score:3, Informative)

      It all depends on if the particulate, after settling, causes a net reflection or absorption of radiation. This would depend on the precise chemical makeup of the particulate, the altitude dispersed, and the process that dispersed it(temp, pressure, velocity, etc).
      • Which is why talk of geoengineering with aerosols are treated with hand-wringing by real scientists. Particulates and aerosols behave differently at different altitudes, times of the year & day, etc. You can't just set up a company and say, "I'll shoot salt water up in the air!" or "I'll eject sulfur particulates high up!" and think you've solved anything, let alone global warming. :-)

    • by goodmanj (234846) on Saturday October 30, 2010 @12:38PM (#34073940)

      To oversimplify:

      Volcanoes generally release sulfate aerosols -- tiny clear droplets of sulfuric acid -- and pale grey ash particles. These are lighter in color than the ground below them, so adding them to the atmosphere makes the planet as a whole lighter in color, so it reflects more sunlight, causing cooling.

      Black soot is black: adding it to the atmosphere *darkens* the planet overall, causing it to heat up.

  • by PolygamousRanchKid (1290638) on Saturday October 30, 2010 @09:33AM (#34072644)

    The fuel apparently expels a black carbon soot into the stratosphere when burned with nitrous oxide

    You don't burn nitrous oxide, you just inhale it.

    Is, like, our druggie-head culture going to Hell in a hand basket?

    Oh, what a sorry state of the nation, when teenagers don't know how to do whippets anymore . . .

    • Re: (Score:3, Funny)

      by Anonymous Coward
      Seriously! We can use the N2O to send six people into space, or use the same amount to make, like, a million people think they're in outer space - for about thirty seconds anyway.
    • Re: (Score:3, Funny)

      by nacturation (646836) *

      The fuel apparently expels a black carbon soot into the stratosphere when burned with nitrous oxide

      You don't burn nitrous oxide, you just inhale it.

      I thought that's exactly what's happening. The rocket engine inhales the nitrous oxide which is what makes it get so high.

  • by arikol (728226) on Saturday October 30, 2010 @09:34AM (#34072652) Journal

    The reason they went with this motor design was simplicity of construction, low chance of explosions and other nasty failure modes, reliability and price. Yet another is that this motor type can be shut off before the burn is complete (unlike the SpaceShuttle side boosters which use a thermite-like mixture (with a rubber-like binder) which provides its own oxidizer.
    The Rutan design uses nitrous oxide as an oxidizer to be able to better control the burn.

    I don't recall environmental factors being discussed when Rutan and co. were publicizing the motor design.
    The engineering reasons are perfectly good, though, and research into figuring out a blend which spews out less soot would probably be good from all standpoints (possibly even upping the specific energy content of the motor/fuel)

    • by khallow (566160)

      I don't recall environmental factors being discussed when Rutan and co. were publicizing the motor design.

      Well, they aren't using hydrazine and fuming red nitric acid. Toxicity of the fuel did play a part in their choices.

    • by Teancum (67324)

      Scaled Composites & Richard Branson came out with a statement that they are fully aware of some of these issues and that they are working on alternative fuels to perhaps mitigate this problem too. As you point out, there were many reasons why they went with this particular solution, where vehicle safety is one of the things that was of primary importance where they don't necessarily want to be on the bleeding edge of technical performance. The goal is to have an airline quality of performance for roug

    • Yet another is that this motor type can be shut off before the burn is complete (unlike the SpaceShuttle side boosters

      Note that while Shuttle SRB's cannot be shut off, this was a design decision made by NASA - not a universal property of solid fuel motors. Shutting off solids in flight has been pretty much routinely done since the late 1950's.

      • by arikol (728226)

        No, you are wrong on this. A true (simple) solid rocket CANNOT be shut down once lit. Shut-off requires removing the oxidizer, which in case of a true solid rocket is embedded within the material.

        Mixed designs (hybrid rockets) have been available, but are generally of a lower specific energy, and require a pressurized oxidizer of some sorts (liquid or gas) meaning that the oxidizer has to be kept separate and in a heavy pressurized bottle with all the plumbing required.

        A simple solid rocket is, well, simple

        • No, you are wrong on this. A true (simple) solid rocket CANNOT be shut down once lit. Shut-off requires removing the oxidizer, which in case of a true solid rocket is embedded within the material.

          No, *you* are wrong. Worse yet, when told you're wrong, you just parrot what you've heard before and make nonsensical claims and erect strawmen to 'prove' yourself correct.

          The fact is that unconfined, all modern solid fuel does is essentially smolder - they require high pressure to actually burn. Vent the

          • by arikol (728226)

            Seriously?
            Ok.
            Venting generally does not shut down the burn, but does get thrust to zero, leaving you with a dangerous hunk of smoldering explosives. Not much room for error.
            Venting has ONLY been used on unmanned systems, and relatively small ones at that, because venting a LARGE solid rocket generally involves blasting the casing apart longitudinally. Venting the casing really is not as simple as you make it out to be, because the burn chamber needs to be vented, and that's inside the cast motor bit. THAT'S

  • by khallow (566160) on Saturday October 30, 2010 @09:57AM (#34072772)
    While the Wired story doesn't show blatant bias unlike the Nature story, "Space tourism to accelerate climate change" [nature.com], it still remains that no mechanism for the claimed climate changes has been described. It's just, "These guys ran their computer model and this is what they got." That's extremely unhelpful.
    • by khallow (566160)
      I have no idea why my above comment got modded "troll". I was just saying that nobody in the story explains why it happens. In most science stories, somebody explains things even if it's a bit crude and simplified. Here, is it due to some non-linear effect from reduced heating at the latitudes where the soot is most prevalent? Is it due to cloud nucleation in the equatorial regions? Is soot raining down on the ice caps and increasing their albedo? At best, we have the following:

      The results are surprising, says Simone Tilmes, an atmospheric chemist at NCAR who was not involved in the study. "What's interesting is that if you force the whole climate system in one point or one hemisphere you can make big changes," she says. Further, more detailed studies examining the circulation of particulates will to help to reduce some of the uncertainties in the model, she adds.

      How is the system being force

    • by goodmanj (234846) on Saturday October 30, 2010 @12:45PM (#34073986)

      it still remains that no mechanism for the claimed climate changes has been described. It's just, "These guys ran their computer model and this is what they got." That's extremely unhelpful.

      If you have access to AGU journals, you should read the original article [agu.org]. It's quite detailed about the mechanisms involved.

      Even without the original article, the mechanism here really isn't rocket science. Black stuff in the atmosphere makes the planet absorb more sunlight and therefore heat up. Really simple. To go beyond mechanism to get a numerical estimate of climate change, you unavoidably need a model. And take it from me, the one they're using is a good one.

      You're using a lot of breath to cast doubt on the results here, with far less justification for your conclusions than the Nature and Wired authors you're attacking.

      • by khallow (566160)

        Even without the original article, the mechanism here really isn't rocket science. Black stuff in the atmosphere makes the planet absorb more sunlight and therefore heat up. Really simple. To go beyond mechanism to get a numerical estimate of climate change, you unavoidably need a model. And take it from me, the one they're using is a good one.

        Thank you for that information.

      • To go beyond mechanism to get a numerical estimate of climate change, you unavoidably need a model. And take it from me, the one they're using is a good one.

        Michael Mann is that you?

  • Pure Nonsense (Score:1, Flamebait)

    by Azghoul (25786)

    Give me a break.

    Just guessing here, but I'd bet good money that granola crunching campers "cause" more global warming burning their frigging campfires.

  • I think when a technology is just developing, it is sometimes really hard to say what the costs are going to be. It is easy to over think the problem and never even get a prototype, much less a production model. Often we do not see the full effects, or lack thereof, until mass production sets in.

    When the shuttle was being developed, it was thought it would be much more environmentally destructive that it turned out to be. OTOH, if we were to have shuttle launches every day, we would probably see an una

  • is obviously a Saturn V Prius...
  • Take up bottled CO2 up with each launch and jettison it towards the sun.
    The ultimate form of carbon credits.

  • The greenhouse gas emissions of all the space bound rockets in the world would be insignificant compared to say the fireworks and rockets used on 4th July, or even those used on 5th November (for UK and NZ readers).

    And what about the environmental impact of next weeks midterm elections, all that advertising that goes straight into the garbage (its glossy so won't recycle) or even the gas used by people driving to the polling booth.

    • Yes, almost everything we do pollutes, but that doesn't mean that we shouldn't consider the enviromental impacts.

      There also aren't very many fireworks that reach the edge of space.
  • The fuel apparently expels a black carbon soot into the stratosphere when burned with nitrous oxide, which could be contributing to global climate changes, like shrinking the icecaps.

    Give me a break. The environmental damage contributed by plain tourism itself (e.g. flights/cruise ships/train/buses, not to mention hotels, theme parks, etc) would be orders of magnitude more than anything *space* tourism can do for the foreseeable decade or two.

    Let me guess, a more "environmental friendly" engine is available from those scientists' company/sponsor?

    • by goodmanj (234846) on Saturday October 30, 2010 @12:48PM (#34074004)

      A very important distinction: planes, ships, and buses are designed to run clean, with little or no soot output. They also operate in the troposphere, where rainfall "washes" the atmosphere and cleans out the soot and other particles regularly. This is a very different thing than NO+rubber rockets (which are literally as clean-burning as a burning tire) in the stratosphere, where small particles tend to linger for years.

      • by goodmanj (234846)

        Oh, and also: the authors aren't claiming that these rockets are a bigger deal than traditional tourism: the point is that the environmental impact of space tourism may be very large *relative* to the size of the industry.

      • by khchung (462899)

        A very important distinction: planes, ships, and buses are designed to run clean, with little or no soot output. They also operate in the troposphere, where rainfall "washes" the atmosphere and cleans out the soot and other particles regularly.

        Are they even comparable? Tens (if not hundreds) of thousands flights/ships/buses per day, to, what? One flight per year if they are lucky? No matter where the soot were spilled.

        What's more, there is a more eloquent responds here http://science.slashdot.org/comments.pl?sid=1846728&cid=34072712 [slashdot.org], and the important part is this:

        They take three flights every day for 40 years,

        How many decades away would it be when we even remotely possible to have *3* space tourist flights every day?

        • by goodmanj (234846)

          How many decades away would it be when we even remotely possible to have *3* space tourist flights every day?

          As the original article points out, there are three companies planning to do this, and their business models plan for 1 flight a day. For *suborbital* rockets using simple propulsion systems, this is not not impossible, if the demand is there. The article says, "what if that actually happened?"

          Are they even comparable? Tens (if not hundreds) of thousands flights/ships/buses per day, to, what? One f

  • When the Asteroid hits in the year 2157 and wipes out 95% of land dwelling life on earth it will be worth it because the asteroid impacted upon a earth that shunned space travel and the pristine wilderness destroyed by the asteroid strike was a far better thing for all those now extinct species than having space tourism and colonization and the infrastructure that it requires to divert the asteroid. Oh well....

    Hopefully in another 65 million years evolution will evolve another intelligent species that can

  • Like the type dumped into the atmosphere by the Space Shuttle since 1981? Lets not worry....but now that the shuttle is nearly is nearly at an end and non-US space flights are ready to start, let the complaints begin! Sour grapes anyone?
    • by Wyatt Earp (1029)

      Umm, all the current space tourism companies that are going to do the flight a day business model are in the US. Down the road we might see them operating out of the Sweden, the UAE, Russia and the EU.

  • Meh. They just need to switch over to a salami rocket [metalab.at] instead. Problem solved.

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