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NASA Announces Enviromentally Friendly Jet Fuel
drama writes "From the Press Release: 'Two years of collaboration between Stanford University, Palo Alto, Calif., and NASA's Ames Research Center, Moffett Field, Calif., have led to the development of a non-toxic, easily handled fuel made from a substance similar to what is used in common candles. The by-products of combustion of the new fuel are carbon dioxide and water; unlike conventional rocket fuel that produces aluminum oxide and acidic gasses, such as hydrogen chloride.' Or for pictures and more info, visit the site."
One of those would be a gigantic step towards a better environment. Unfortunately, this isn't it.
First off: current rocket fuel also lets off C02 so this stuff is at least better than what they're using in that that is _all_ that it lets off.
Second off: it all depends on what the fuel is made from. If it is made from some biomass then it lets off only as much C02 as was recently absorbed from the atmosphere by the plants that it is made from. If it is made from fossil fuels then it is introducing new C02 that hasn't been around for millenia, a serious shock to the global balance.
Third off: C02 from rocket launches isn't nearly as big a deal as it is from cars and heavy industry. It is a drop in the bucket, comparatively. Rockets probably don't have much of a global impact. The problem is the local impact of the toxics that they do let off which directly affects the area surrounding the launch site.
This is NOT a jet fuel, this is a component of a rocket fuel.
In fact, jet fuel is highly refined kerosene, or what the Brits used to call "parafin oil" - because it is a relative of the parafin wax used to seal canning jars, and MAKE CANDLES!
This fuel is a solid form of parafin that, when combined with a liquid or gaseous oxidizer makes a rocket.
The idea is this:
a purely liquid fuel rocket has 2 liquids you have to handle, the oxidizer and the fuel (e.g. LO2 and kerosene, LO2 and LH2, etc.) That's twice as many hoses, twice as many turbopumps, twice as much to go wrong.
A purely solid fuel rocket has no liquids, but once lit off, it will burn until all the fuel is gone. You cannot throttle it down, stop it, or restart it - the best you can do is eject it.
A hybrid rocket uses a solid fuel and a liquid oxidizer. You can throttle it by varying the flow rate on the oxidizer. You can stop it, and restart it again. You still need some tubing for the oxidizer, and a turbopump, but only one.
However, I doubt the only reaction products from this are carbon dioxide and water - more likely you are going to get unburned hydrocarbons, carbon monoxide, carbon dioxide, and water.
Granted, that's nicer than what the SRB's on the Shuttle use - aluminum and ammonium perchlorate IIRC.
www.eFax.com are spammers
when people started talking about 1 launch a month or 1 launch a week, the amount of chlorine that would be placed in the upper atmoshpere whould be enough to destroy the entire ozone layer in a few decades. The only comparable natural phenomena is a volcanic eruption which puts even more chlorine (and other acids) into the upper atmoshere than a shuttle launch.
with china, japan, north korea, europe and boeing all coming on line as rocket launch systems this is going to be increasingly important. Of course not all of these are solid fuel rockets (the culprit).
Some drink at the fountain of knowledge. Others just gargle.
The web site is short on details. They are saying that this new motor has the ability to throttle down and reignite. Depending on how well it can do this, you might be able to replace liquid rockets altogether.
t s/aiaa-hr.pdf, which doesn't indicate that it needs to be cooled, and says the specific impulse is about 20% better than kerosene. I'm assuming they mean Kerosene/LOx and not Kerosene/H2O2.
Also, they are talking about scaling the technology up from the demonstrator to space shuttle size with only a slight size penalty. This is all good, except they didn't mention the specific impulse of the fuel vs. the current solid boosters.
Much better info can be found at http://thomasc.stanford.edu/research.html, which suggests that this "solid" mixture must be cooled to keep it solid. However, a better source is http://store.aiaa.org/images/about/02_TC_Highligh
I would still like to see numbers on this stuff.
According to a quote in this press release, the parrafin-based engines can be throttled, shutdown and even restarted, all of which are impossible with current solid-rocket motors.
It is a petroleum product. But you're on the right track--we already have a way to use biofeuls in your existing diesel car. You can use a manufactured Biodiesel or roll your own more or less for free. And there are some good cars with diesel engines! Trucks, SUVs, Volkswagens and Mercedes.
demi
For those wondering why this is getting funded, or whether rocket exhaust has significant environmental effects, I found an interesting page floating around:
http://www.earthpulse.com/haarp/background.html
some highlights:
--
Saturn V Rocket (1975)
Due to a malfunction, the Saturn V Rocket burned unusually high in the atmosphere, above 300 km. This burn produced "a large ionospheric hole" (Mendillo, M. Et al., Science p. 187, 343, 1975). The disturbance reduced the total electron content more than 60% over an area 1,000 km in radius, and lasted for several hours. It prevented all telecommunications over a large area of the Atlantic Ocean. The phenomenon was apparently caused by a reaction between the exhaust gases and ionospheric oxygen ions. The reaction emitted a 6300 A airglow. Between 1975 and 1981 NASA and the US Military began to design ways to test this new phenomena through deliberate experimentation with the ionosphere.
Orbit Maneuvering System (1981)
Part of the plan to build the SPS space platforms was the demand for reusable space shuttles, since they could not afford to keep discarding rockets. The NASA Spacelab 3 Mission of the Space Shuttle made, in 1981, "a series of passes over a network of five ground based observatories" in order to study what happened to the ionosphere when the Shuttle injected gases into it from the Orbit Maneuvering System (OMS). They discovered that they could "induce ionospheric holes" and began to experiment with holes made in the daytime, or at night over Millstone, Connecticut, and Arecibo, Puerto Rico. They experimented with the effects of "artificially induced ionospheric depletions on very low frequency wave lengths, on equatorial plasma instabilities, and on low frequency radio astronomical observations over Roberval, Quebec, Kwajelein, in the Marshall Islands and Hobart, Tasmania" (Advanced Space Research, Vo1.8, No. 1, 1988).
Innovative Shuttle Experiments (1985)
An innovative use of the Space Shuttle to perform space physics experiments in earth orbit was launched, using the OMS injections of gases to "cause a sudden depletion in the local plasma concentration, the creation of a so called ionospheric hole." This artificially induced plasma depletion can then be used to investigate other space phenomena, such as the growth of the plasma instabilities or the modification of radio propagation paths. The 47 second OMS burn of July 29, 1985, produced the largest and most long-lived ionospheric hole to date, dumping some 830 kg of exhaust into the ionosphere at sunset. A 6 second, 68 km OMS release above Connecticut in August 1985, produced an airglow which covered over 400,000 square km.
During the 1980's, rocket launches globally numbered about 500 to 600 a year, peaking at 1500 in 1989. There were many more during the Gulf War. The Shuttle is the largest of the solid fuel rockets, with twin 45 meter boosters. All solid fuel rockets release large amounts of hydrochloric acid in their exhaust, each Shuttle flight injecting about 75 tons of ozone destroying chlorine into the stratosphere. Those launched since 1992 inject even more ozone-destroying chlorine, about 187 tons, into the stratosphere (which contains the ozone layer)