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Author
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Topic: Space shuttle launch pollution
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Max Q Member Posts: 399 From: Whyalla South Australia Registered: Mar 2007
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posted 06-14-2008 06:23 AM
I have watched many web casts in awe of shuttle and booster launches. I visited a launch photo site found here on cS and it showed the plume left by Discovery 4 hours after lift off. I was wondering about the pollution caused by shuttle and other space boosters also for those of you who have seen these events.What is the smell of a launch? How long on a still day does the smoke generated hang around? What is the make up of the smoke? |
Jay Chladek Member Posts: 2272 From: Bellevue, NE, USA Registered: Aug 2007
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posted 06-14-2008 09:57 AM
Well, for most liquid fueled boosters, the smoke is mostly steam. It is the SRBs that tend to generate some particulates that are considered toxic and these are caused by the curing and binding agents used in the fuel as opposed to the fuel itself. The SRB plumes on a shuttle produce a hydrochloric acid cloud and as a result (if I remember correctly), nobody can approach the launch pad utilized for at least a couple hours until concentrations in the air drop to safe levels. NASA also typically performs environmental impact studies around the pads after each launch since they are built on a wildlife preserve and it doesn't seem as though the surrounding areas of vegitation get harmed much (if at all) by the residue from the SRBs. Listening to the audio commentary on my DVD of Armageddon (Criterion collection version, including audio commentary from the director, the lead cameraman and astronaut Joe Allen), they talked about the survey they did to the cameras used to film the launches for the film, and even with the all clear given, there was still an almost overpowering acidic smell in the air that made a couple of their camera techs want to vomit. That was the extent of it though. When I was down at the press site for STS-121, we had a bulletin a couple days before that with prevailing winds, there was a good chance that some particulate matter from Discovery's liftoff would get blown back towards the press site. I asked one of the other press guys if he ever had been pelted by SRB debris and he said yes, on a couple of occassions. He said normally it isn't anything to worry about. If it gets on the car, just try to get it washed off soon so one doesn't risk it etching the paint. Biggest thing was to not get a particulate in your eye since it would burn like a drop of acid rain and would need to be flushed out at a first aid station. After STS-121 launched, sure enough the main smoke plume from the SRBs was headed towards the press site, so I beat feet inside and stayed there for a little while before heading out to the airport. When I got to the rental car I had used, I noticed there were clumpy particles of a fine gray material on the paint, presumeably left over SRB particulates. It was sort of like volcanic ash residue. It didn't have a smell to it or anything. I missed catching my flight home that evening, so I made sure to stop at a car wash to get the stuff off when I had the chance. |
Ben Member Posts: 1896 From: Cape Canaveral, FL Registered: May 2000
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posted 06-14-2008 12:31 PM
The corrosive exhaust of SRBs contains hydrogen chloride which mixes with water to become hydrochloric acid; aluminum oxide; chlorine which measurably depletes ozone; carbon dioxide; and nitrogen oxide of more than one variety.The Air Force did many studies on the effects of large SRBs on the atmosphere, namely from the shuttle and Titan IV and concluded that some nine shuttles and six Titans per year accounted for a bit less than one percent of the world's annual ozone depletion. Part of the tests included flying a WB-57 into the exhaust plumes after launch. The Air Force cited the environment as one of its main reasons for retiring the Titan IV. You can view data from those studies here: Rockets and the Ozone Layer IMPACT OF ROCKETS ON STRATOSPHERIC OZONE DEPLETION Space Shuttle & Ozone Layer Damage Article: Poisoned plumes Rockets fueled with only hydrogen and oxygen, of which there is only the Delta IV, produce only water vapor; rockets powered by kerosene produce carbon dioxide. The process to manufacture hydrogen and kerosene is also pollutive. Those are what I would call the facts. I wouldn't mind seeing SRBs retired, but in the overall goal of space exploration I would say it's worth the cost. |
ea757grrl Member Posts: 729 From: South Carolina Registered: Jul 2006
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posted 06-14-2008 03:06 PM
The one-page safety information sheet in the information package NASA issues to launch guests includes a general safety statement, a lightning warning, and the following (which was also read over the bus PA system enroute to the viewing site):ACID RAIN STATEMENT - At ignition, the Space Shuttle's twin solid rocket boosters produce an exhaust cloud containing drops of hydrochloric acid. This cloud drifts with the wind after the launch, slowly dissipating as it travels. These droplets are not strong enough to cause anything other than a minor irritation and are easily rinsed off with water. - Launch viewing sites are far enough away from the launch site that there is ample time for visitors to return to the bus. It is imperative that you listen for all announcements and strictly follow all instructions provided by NASA. Fortunately, we didn't get the "acid rain" effect at the Banana Creek viewing site for STS-124, but the folks I watched the launch with did have stories of when the wind did shift their way during previous launches, and of getting little flecks on them. After hearing their stories, I'm just as glad to have avoided it. STS-124 was a beautiful launch. We didn't get the full sound and fury you read about over where we were, but you could definitely hear something was going on over at 39A. It was spectacular nonetheless. jodie |
Max Q Member Posts: 399 From: Whyalla South Australia Registered: Mar 2007
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posted 06-15-2008 02:05 AM
Thanks for the information guys I'm surprised at some of it and I even more surprised that NASA intend to stay with solids in the future. Is exploration worth it at any cost? |
Jay Chladek Member Posts: 2272 From: Bellevue, NE, USA Registered: Aug 2007
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posted 06-15-2008 04:34 AM
Are we talking "any cost" or a balance of the cost versus the benefits? Where does one draw the line? Shuttle alone has flown several space laboratories and dedicated research platforms to look down on Earth and measure environmental impacts. Without the capability shuttle brings, quite a few of those payloads would never have flown, hence nothing to collect data.I would say in the case of NASA, if SRBs had been a larger pollution hazard then they seem to be, there probably would have been more effort to come up with an LRB about ten years ago when initial studies were done concerning such a system to replace the SRBs. Reason being is that KSC is built on a wilderness preserve (federal land) and environmental studies take place there all the time. As such, there is plenty of data to measure the effects of rocket launches in that part of Florida. If and when Orion begins to fly, chances are the flight rate will only be about two or three flights a year to the ISS if we are talking four to six month rotation rates of six crewmembers. Since Aries 1 would use a single SRB, then we are talking a reduction in pollution of about 1/5th of what we see in a given year with five shuttle launches. Aries V won't fly until 2022 at the earliest it seems and at most I can only see maybe five flights a year maximum if the Lunar program ramps up the way NASA wants it to. Of course, solids are used in other space programs as well with Ariane V being a prime example. That being said though, I do wish more money was channeled into researching cleaner solid fuels, since to my knowledge it is the binding agents, rather then the fuel itself, that accounts for the majority of pollutants in shuttle SRB exhaust plumes. |
Max Q Member Posts: 399 From: Whyalla South Australia Registered: Mar 2007
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posted 06-15-2008 08:02 PM
Jay I take your point and agree that a lot of good has come from the shuttle and I'm sure we have advances in science that have came much quicker as a direct result because of shuttle. But as Ben said quote: Originally posted by Ben: The Air Force did many studies on the effects of large SRBs on the atmosphere, namely from the shuttle and Titan IV and concluded that some nine shuttles and six Titans per year accounted for a bit less than one percent of the world's annual ozone depletion. Part of the tests included flying a WB-57 into the exhaust plumes after launch.
...this being taken as fact a bit less than one percent is a huge amount for just one source (SRB). The answer god only knows but it will not come cheap. |
Jay Chladek Member Posts: 2272 From: Bellevue, NE, USA Registered: Aug 2007
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posted 06-15-2008 11:08 PM
I know what you mean.I think Titan also got retired as well due to other factors in its design, a big one being that the core stages of the booster utilize hypergolic fuels as the primary fuel and oxidizer. Atlas V and Delta IV heavy are much better boosters by comparison and can haul stuff up in the Titan power class now. Granted shuttle orbiter and many satellites also utilize hypergolics, but Titan was the last US booster to use it for the primary rocket motors. The Soviets utilized hypergolic rocket motors in their Proton boosters as well and indeed they still have Proton handy in their arsenal. But today it is only utilized to fly large payloads, such as the first two modules of the ISS, as opposed to flying most of the payloads they send up. That is what they have Zenit and the R-7 Soyuz boosters for. As I understand it, they mandated a move away from using hypergolics in future booster designs after one Proton apparently blew up right after launch and spread unburned hypergolic fuel all over the place. Cleaning up after a mess like that I imagine tends to potentially have a more dramatic environmental impact than acid rain from SRBs. | |
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