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What is the cheapest rocket fuel & oxidizer and how much does it cost?
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trident
May 20, 2017, 3:22:58 PM5/20/17
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I figured that ethanol is the cheapest fuel with going as low as 1 cent per kg. But what about oxidizer? Liquid oxygen can go as low as 66 dollars per tonne but is the best price one can get, taking into consideration Isp differences?
0something0
May 20, 2017, 4:33:02 PM5/20/17
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On Saturday, May 20, 2017 at 3:22:58 PM UTC-4, trident wrote:
> I figured that ethanol is the cheapest fuel with going as low as 1 cent per kg. But what about oxidizer? Liquid oxygen can go as low as 66 dollars per tonne but is the best price one can get, taking into consideration Isp differences?
Check out this:
> I figured that ethanol is the cheapest fuel with going as low as 1 cent per kg. But what about oxidizer? Liquid oxygen can go as low as 66 dollars per tonne but is the best price one can get, taking into consideration Isp differences?
https://en.wikipedia.org/wiki/Category:Rocket_oxidizers
"Wikipedia is not a credible source" -Every teacher ever
Greg Goss
May 20, 2017, 4:55:21 PM5/20/17
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a vehicle fuel and much worse than diesel.
--
We are geeks. Resistance is voltage over current.
Wolffan
May 21, 2017, 10:58:20 AM5/21/17
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On 2017 May 20, trident wrote
(in article<08ca389c-116b-48f2...@googlegroups.com>):
you need to define your terms. ‘Cheap’ in what way? Cheapest for high
specific impulse? Cheapest for high thrust? Cheapest by mass? Cheapest by
volume? Are you going with just chemical systems, or are electrical or
nuclear allowed to play?
Hint: ethanol is a very bad chemical fuel. High mass, low density, poor
specific impulse. Liquid hydrogen, kerosine, and gasoline are all far better.
Yes, it’s cheap by mass, but you need a _lot_ of it because of its low
specific impulse. Your mass ratio is going to suck. And its low density means
that the tanks to hold it are going to be large. It might cost less per kilo,
but given the number of kilos you’ll need plus the mass of tankage to hold
all those kilos, ethanol would cost more than, say, kerosine. Worse, burning
ethanol simply doesn’t generate all that much thrust, so you’ll have a
problem getting sufficient thrust to get off the ground if you build a rocket
which carries enough ethanol fuel to run a significant mission.
remember always: deltavee = veesube * MR, where deltavee is your total
mission change in velocity, veesube is the exhaust velocity your rocket puts
out, and MR is your mass ratio, the ratio between the mass of rocket plus
consumables at the start of the mission to the mass of whatever’s left at
the end. worse, your thrust is dependent on the veesube _and_ your fuel flow
rate. Unless your veesube is very, very, VERY high indeed, having a low MR
and therefore a low fuel flow rate (you can’t have a _high_ rate if you
just don’t have the fuel, now can you?) means that you’re going to have a
low thrust. Ion systems and nuclear hot jets of the NERVA type have nice high
veesubes and nice low MRs... and low thrust. Ethanol would give low veesube,
high MR... and, because of the low veesube, low thrust.
There would be a _reason_ why serious liquid-fueled rockets use kerosine, or
hydrogen with liquid oxygen for oxidizer, or hydrazine and nitric, or pretty
much anything except ethanol. Some rockets used a mix of hydrazine and
methanol; see further C-Stoff and the Me-163. So far as I know no-one used
ethanol, either pure or in a mix. It should be noted that C-Stoff was
notoriously highly troublesome to handle.
(in article<08ca389c-116b-48f2...@googlegroups.com>):
specific impulse? Cheapest for high thrust? Cheapest by mass? Cheapest by
volume? Are you going with just chemical systems, or are electrical or
nuclear allowed to play?
Hint: ethanol is a very bad chemical fuel. High mass, low density, poor
specific impulse. Liquid hydrogen, kerosine, and gasoline are all far better.
Yes, it’s cheap by mass, but you need a _lot_ of it because of its low
specific impulse. Your mass ratio is going to suck. And its low density means
that the tanks to hold it are going to be large. It might cost less per kilo,
but given the number of kilos you’ll need plus the mass of tankage to hold
all those kilos, ethanol would cost more than, say, kerosine. Worse, burning
ethanol simply doesn’t generate all that much thrust, so you’ll have a
problem getting sufficient thrust to get off the ground if you build a rocket
which carries enough ethanol fuel to run a significant mission.
remember always: deltavee = veesube * MR, where deltavee is your total
mission change in velocity, veesube is the exhaust velocity your rocket puts
out, and MR is your mass ratio, the ratio between the mass of rocket plus
consumables at the start of the mission to the mass of whatever’s left at
the end. worse, your thrust is dependent on the veesube _and_ your fuel flow
rate. Unless your veesube is very, very, VERY high indeed, having a low MR
and therefore a low fuel flow rate (you can’t have a _high_ rate if you
just don’t have the fuel, now can you?) means that you’re going to have a
low thrust. Ion systems and nuclear hot jets of the NERVA type have nice high
veesubes and nice low MRs... and low thrust. Ethanol would give low veesube,
high MR... and, because of the low veesube, low thrust.
There would be a _reason_ why serious liquid-fueled rockets use kerosine, or
hydrogen with liquid oxygen for oxidizer, or hydrazine and nitric, or pretty
much anything except ethanol. Some rockets used a mix of hydrazine and
methanol; see further C-Stoff and the Me-163. So far as I know no-one used
ethanol, either pure or in a mix. It should be noted that C-Stoff was
notoriously highly troublesome to handle.
Thomas Koenig
May 21, 2017, 11:31:34 AM5/21/17
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Wolffan <AKWo...@gmail.com> schrieb:
> So far as I know no-one used
> ethanol, either pure or in a mix.
The V-2 used an ethanol-water mixture. Does that qualify? :-)
This was used for its cooling properties, and also (AFAIK) to keep
down the temprature in the combustion chamber.
> So far as I know no-one used
> ethanol, either pure or in a mix.
This was used for its cooling properties, and also (AFAIK) to keep
down the temprature in the combustion chamber.
alie...@gmail.com
May 21, 2017, 1:08:27 PM5/21/17
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Mark L. Fergerson
alie...@gmail.com
May 21, 2017, 1:19:31 PM5/21/17
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As for the oxidizer, considerations other than expense and efficiency come into play in the real world. For instance, fluorine is a much better oxidizer than oxygen, but I'd rather gasoline-fluorine rockets weren't launched from my planet.
Mark L. Fergerson
Wolffan
May 21, 2017, 7:13:54 PM5/21/17
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On 2017 May 21, Thomas Koenig wrote
(in article <ofsbsl$lqn$1...@newsreader4.netcologne.de>):
> Wolffan <AKWo...@gmail.com> schrieb:
>
> > So far as I know no-one used
> > ethanol, either pure or in a mix.
>
> The V-2 used an ethanol-water mixture. Does that qualify? :-)
the water was there to improve the thrust, though it made the mass ratio even
worse. (more ‘fuel’ to flow).
And, yes, I’d forgotten about the A4/V2.
(in article <ofsbsl$lqn$1...@newsreader4.netcologne.de>):
> Wolffan <AKWo...@gmail.com> schrieb:
>
> > So far as I know no-one used
> > ethanol, either pure or in a mix.
>
> The V-2 used an ethanol-water mixture. Does that qualify? :-)
worse. (more ‘fuel’ to flow).
And, yes, I’d forgotten about the A4/V2.
trident
May 22, 2017, 5:35:35 PM5/22/17
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Wolffan Lox/ethanol seems to have ISp only slightly inferior to that of lox/kerosene but RP-1 costs 3.5 USD per gallonn so about dollar per kilogram whereas etanol can be -probably be as low as one CENT per kilo.
http://www.astronautix.com/l/loxalcohol.html
http://www.astronautix.com/l/loxkerosene.html
I will disclose my interest. I am trying to write a hard SF story where Ginormous megarocket with miliions of tons of wight is built to launch half a milion ton payload to orbit. To cut the costs it is built in shipyard like SEA DRAGON and I assume the costs can be the order of 1 one bilion USD per rocket (oil tanker even with half a milion ton of displacement can costs up to 120 milion USD). However in this design the costs of fuel is still ginormous. 16 milions tons of fuel would still cost like a 16 bilions usd ( or that order). Etanol shouls save the weight but liquid oxygen i still to expensive for such a project even with 66 dollars per tonne. So I would kill for some cheper oxidizer with comparable performance, assuming there is one.
http://www.astronautix.com/l/loxalcohol.html
http://www.astronautix.com/l/loxkerosene.html
I will disclose my interest. I am trying to write a hard SF story where Ginormous megarocket with miliions of tons of wight is built to launch half a milion ton payload to orbit. To cut the costs it is built in shipyard like SEA DRAGON and I assume the costs can be the order of 1 one bilion USD per rocket (oil tanker even with half a milion ton of displacement can costs up to 120 milion USD). However in this design the costs of fuel is still ginormous. 16 milions tons of fuel would still cost like a 16 bilions usd ( or that order). Etanol shouls save the weight but liquid oxygen i still to expensive for such a project even with 66 dollars per tonne. So I would kill for some cheper oxidizer with comparable performance, assuming there is one.
Message has been deleted
Kavanagh
May 23, 2017, 4:59:10 PM5/23/17
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As a previous poster wrote, specific impulse is the way to go. $/kg in orbit basicly. Long time since I looked at this, but if memory serves, for relatively low masses (and without safety considerations) unsymmetrical dimethylhydrazine (UDMH) + nitrogen tetroxide (N2O4) or LOX is a good combination.
For large masses (hundreds of thousands of tons, the more massive the smoother the ride), Orion is a no brainer, but the greenies and PC'ers shut that down half a century ago. No oxidiser, just reaction mass.
Mike Van Pelt
May 24, 2017, 4:59:09 PM5/24/17
to
In article <8c156f9c-67f7-4c42...@googlegroups.com>,
cryogenic, to boot. Of course, the "Not on *MY* planet!"
thing still applies.
Liquid Ozone would have marvelous ISP, if only it didn't
self-detonate "just because it feels like it".
I tend to want to avoid substances on Dr. Derek Lowe's
"Things I Won't Work With" list.
--
"The urge to save humanity is almost | Mike Van Pelt
always a false front for the urge to rule." | mvp at calweb.com
-- H.L. Mencken | KE6BVH
nu...@bid.nes <alie...@gmail.com> wrote:
>As for the oxidizer, considerations other than expense and
>efficiency come into play in the real world. For instance,
>fluorine is a much better oxidizer than oxygen, but I'd rather
>gasoline-fluorine rockets weren't launched from my planet.
Chlorine trifluoride is even better, and is storable non-
>As for the oxidizer, considerations other than expense and
>efficiency come into play in the real world. For instance,
>fluorine is a much better oxidizer than oxygen, but I'd rather
>gasoline-fluorine rockets weren't launched from my planet.
cryogenic, to boot. Of course, the "Not on *MY* planet!"
thing still applies.
Liquid Ozone would have marvelous ISP, if only it didn't
self-detonate "just because it feels like it".
I tend to want to avoid substances on Dr. Derek Lowe's
"Things I Won't Work With" list.
--
"The urge to save humanity is almost | Mike Van Pelt
always a false front for the urge to rule." | mvp at calweb.com
-- H.L. Mencken | KE6BVH
Mike Van Pelt
May 24, 2017, 5:04:02 PM5/24/17
to
In article <6ce12db1-5fcb-433b...@googlegroups.com>,
multi-ton lots than LOX. You just pull it out of the air.
Cost is the liquid air machine, the fractional distilation
hardware, and the energy to run it.
trident <tride...@gmail.com> wrote:
>Etanol shouls save the weight but liquid oxygen i still to
>expensive for such a project even with 66 dollars per tonne. So
>I would kill for some cheper oxidizer with comparable
>performance, assuming there is one.
I suspect you're not going to find a cheaper oxidizer in
>Etanol shouls save the weight but liquid oxygen i still to
>expensive for such a project even with 66 dollars per tonne. So
>I would kill for some cheper oxidizer with comparable
>performance, assuming there is one.
multi-ton lots than LOX. You just pull it out of the air.
Cost is the liquid air machine, the fractional distilation
hardware, and the energy to run it.
chowhan...@gmail.com
Jan 17, 2018, 5:16:45 AM1/17/18
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