Polynitrogen Rocket Fuel

Damon Hill wrote:
But a solid propellant with that kind of Isp would be
smaller, lighter and much easier to handle than a cryogenic
stage; should be a significant performance gain, and cheaper too.

Even a high performance solid booster would not
necessarily be preferable to a cryogenic liquid
booster. Solids are very finicky, require extensive
preparation (and inspection), tend to be fairly heavy,
and are not very suitable for mass production. Even a
solid stage with the same Isp as a cryogenic stage
would not necessarily have the same performance.
Especially for Lox/Kerosene, the dry mass fraction of
advanced liquid stages tends to be lower than that of
solid stages. Even with all the difficulties of
handling cryogenic propellants they are still fairly
easy to manufacture and handle compared to solids.

Not to mention the many serious safety hazards of
solids, or CG issues.


Solids are great for storable propellants in disposable
vehicles like missiles but are often more trouble than
they're worth in launch vehicles.

Damon Hill wrote in message . 134...
Yup. Chemical rockets are already near their maximum
theoretical limits Isp-wise.


But a solid propellant with that kind of Isp would be
smaller, lighter and much easier to handle than a cryogenic
stage; should be a significant performance gain, and cheaper too.

--Damon

Are you guys sure that chemical propellants are already maxed out?
What about solid hydrogen particles suspended in liquid helium? I read
that's being worked on too, but the extreme temperatures would make it
a very difficult fuel to handle.

What about Meta-Stable Metallic Hydrogen? It's a theoretical version
of hydrogen that might be able to survive at STP. Metallic hydrogen
has only been observed briefly under extreme pressure, and nobody
really knows if a meta-stable version could be made, but apparently
there may be a theoretical possibility.

Of course, if it could exist at STP, then how come nobody's ever
encountered natural samples of it, like with diamond?

What would you all recommend as a promising High-Energy Density
Material?

(sanman) wrote in
om:

Damon Hill wrote in message
. 134...
Yup. Chemical rockets are already near their maximum
theoretical limits Isp-wise.


But a solid propellant with that kind of Isp would be
smaller, lighter and much easier to handle than a cryogenic
stage; should be a significant performance gain, and cheaper too.

Are you guys sure that chemical propellants are already maxed out?
What about solid hydrogen particles suspended in liquid helium? I read
that's being worked on too, but the extreme temperatures would make it
a very difficult fuel to handle.

Not all sure what this is about...do you mean atomic hydrogen? That
is, single atoms of hydrogen. The heat of recombination is considerable
and the exhaust would be low molecular weight, so specific impulse
would be up in the low nuclear thermal range, at least.

Sounds like a headache to manufacture, store and use. Helium's not
all that common a commodity either.

What about Meta-Stable Metallic Hydrogen? It's a theoretical version
of hydrogen that might be able to survive at STP. Metallic hydrogen
has only been observed briefly under extreme pressure, and nobody
really knows if a meta-stable version could be made, but apparently
there may be a theoretical possibility.
Of course, if it could exist at STP, then how come nobody's ever
encountered natural samples of it, like with diamond?

Well, there's the problem--you can't fly with unobtanium.

What would you all recommend as a promising High-Energy Density
Material?

I've heard of research into hydrazine-like chemistry, but evidently
nothing's come of it. Supposed to produce a liquid monopropellant
with an Isp in the low 400s.

Screw chemistry!

Nuclear thermal, preferably gaseous-core NT. At least we know nuclear
fission works, and solid core NTRs have been demonstrated.

--Damon

(sanman) wrote in message . com...
Damon Hill wrote in message . 134...



What would you all recommend as a promising High-Energy Density
Material?

Well, there's always Anti-Matter:

http://www.navyseals.com/community/a...le.cfm?id=4614

sanman wrote:
Are you guys sure that chemical propellants are already maxed out?
What about solid hydrogen particles suspended in liquid helium? I read
that's being worked on too, but the extreme temperatures would make it
a very difficult fuel to handle.

What about Meta-Stable Metallic Hydrogen? It's a theoretical version
of hydrogen that might be able to survive at STP. Metallic hydrogen
has only been observed briefly under extreme pressure, and nobody
really knows if a meta-stable version could be made, but apparently
there may be a theoretical possibility.

Of course, if it could exist at STP, then how come nobody's ever
encountered natural samples of it, like with diamond?

It's somewhat borderline to call these things "chemical"
propellants. Rockets which use the energy of more or
less ordinary chemical bonds have reached nearly their
theoretical potential already. Rockets which use exotic
chemical reactions such as the decomposition of Metallic
Hydrogen, or better yet: Atomic Hydrogen, could have
higher performance, but have yet to be proved and
really belong in a different class.


What would you all recommend as a promising High-Energy Density
Material?

Uranium, Plutonium, Deuterium...

On 1 Nov 2004 19:49:30 -0800, Eric Moore wrote:

(sanman) wrote in message
. com...
Damon Hill wrote in message
. 134...



What would you all recommend as a promising High-Energy Density
Material?

Well, there's always Anti-Matter:

http://www.navyseals.com/community/a...le.cfm?id=4614

Oh, just wonderful! Just what we need. A more powerful bomb..
Antimatter is a great source of energy if used intelligently.
In the hands of the military it can only spell death.
Still I suppose it was inevitable that the millitary would investigate
the possibility. Luckily so far antimatter has only been produced in
minuscule quantities. It is currently not a option either as a fuel
source or a weapon. Since antimatter is made from energy
you have to put more energy into making antimatter than you
are going to get out of it. Currently no one could produce enough
energy to produce a sizable quantity of the substance.
Or even if they could the price would be astronomical.
(I can envision something like giant coils put in the flux passage at IO
perhaps
or over the sun that could generate enough current to power a huge
accelerator
and produce large quantities. But that is just science fiction today.)

--
Using M2, Opera's revolutionary e-mail client: http://www.opera.com/m2/

"Arved Sandstrom" writes:
"sanman" wrote in message
. com...

Look at this page, particularly the 2 bottom-most links:

http://www.dtic.mil/matris/sbir/sttr04/sttr3.html

They mention newly-characterized stable salt compounds containing the
recently developed N5+ cation, which offers a lot of nitrogen in a
small space.

I'd read that N5+ was developed at China Lake, and while it's very
promising for energy density, it was notoriously unstable. But these
new fluoroantimonide salts apparently overcome that problem
effectively.

If the stuff is stable against impact and has temperature stability
upto 70-deg C, then why not design spaceships around this kind of
rocket fuel? But with the fluorine in it, will it pollute?

What is its Isp?

My recent experiment with this compound proved its continuing instability.
Although I may not have had the China Lake mix down right. The landlord is
unhappy, the cat is unhappy, the neighbours are unhappy, the plants are
unhappy, I am wounded, and hence I recommend further study.


Nit: N5+ was developed by Drs. Karl Christe and Jeffrey Sheehy at Edwards
Air Force Base. About three buildings over from me, FWIW, and so long as
they're playing with this stuff they can *stay* three buildings over. But
credit where credit is due, and that arrow doesn't point to China Lake.


--
*John Schilling * "Anything worth doing, *
*Member:AIAA,NRA,ACLU,SAS,LP * is worth doing for money" *
*Chief Scientist & General Partner * -13th Rule of Acquisition *
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"John Thingstad" wrote in message ...
What would you all recommend as a promising High-Energy Density
Material?

Well, there's always Anti-Matter:

http://www.navyseals.com/community/a...le.cfm?id=4614

Oh, just wonderful! Just what we need. A more powerful bomb..
Antimatter is a great source of energy if used intelligently.
In the hands of the military it can only spell death.
Still I suppose it was inevitable that the millitary would investigate
the possibility. Luckily so far antimatter has only been produced in
minuscule quantities. It is currently not a option either as a fuel
source or a weapon. Since antimatter is made from energy
you have to put more energy into making antimatter than you
are going to get out of it. Currently no one could produce enough
energy to produce a sizable quantity of the substance.
Or even if they could the price would be astronomical.
(I can envision something like giant coils put in the flux passage at IO
perhaps
or over the sun that could generate enough current to power a huge
accelerator
and produce large quantities. But that is just science fiction today.)

Hmm, I'd like to ask more about this.

I don't think it matters that it would take a lot of energy to make
anti-matter for rocket fuel. The thing that counts is energy density,
from what I can see, even if it takes a lot of energy to make the High
Energy Density Material.

But I'd like to ask about the feasibility of using anti-matter as a
rocket fuel.
Are there any lingering environmental dangers posed by anti-matter?
From what I've read, anti-matter will anihilate with ordinary matter,
releasing only X-rays. And of course, X-rays are very hard to capture.
But aside from that, will X-rays fracture enough surrounding nuclei to
lead to lingering radioactive decay radiation that causes
environmental concerns?

Sorry to phrase it in environmental terms, but that's where all the
political controversy is. Politically, nobody seem to care if the
launch crew gets killed, just as long as there isn't some kind
lingering contamination for the general public to feel scared about.

But suppose some material or mechanism could be found to capture and
harness that X-ray energy for propulsive purposes. Wouldn't there be
an inherent amount X-ray exposure to the flight crew? Or could you
tailor the matter-antimatter anihilation to somehow minimize this?

I realize that if your magnetic bottle blinks and you lose the
magnetic containment, then your entire fuel supply will blow up in a
big X-ray burst, and there would be no hope of the flight crew
surviving. But if it only takes a few minutes to get up into space,
then your crew only has to be near the anti-matter for that short
period of time. And how much anti-matter would you really need, just
to get a Saturn-V type of payload into orbit?

Your crew would be sitting at the top of the Saturn-V sized rocket,
and the ittybitty quantity of anti-matter would be sitting all the way
at the bottom of it. And in between the two, filling up all that
interior space of the giant rocket, would be lots of cargo and of
course your propellant. That cargo and propellant wouldn't mind
exposure to X-rays, and could act as a limited shield against a giant
X-ray burst in case your anti-matter fuel accidentally all anihilated
at once.

But is there any way to get lower-frequency EM radiation than X-rays?
How about something more manageable, like UV rays or something?
Comments?

"sanman" wrote in message
om...


Hmm, I'd like to ask more about this.

I don't think it matters that it would take a lot of energy to make
anti-matter for rocket fuel. The thing that counts is energy density,
from what I can see, even if it takes a lot of energy to make the High
Energy Density Material.


It matters because if the cost works out a million dollars
per microgram you wont build many rockets, the current
price is around 62.5 million per microgram


But I'd like to ask about the feasibility of using anti-matter as a
rocket fuel.
Are there any lingering environmental dangers posed by anti-matter?
From what I've read, anti-matter will anihilate with ordinary matter,
releasing only X-rays.

That's true for electrons and positrons (anti-electrons). They'll produce
gamma rays at 511,000 electron volts.
But heavier particles like protons and anti-protons are somewhat messier,
making gamma rays and leaving a spray of secondary particles that eventually
decay into neutrinos and low-energy gamma rays.

And of course, X-rays are very hard to capture.
But aside from that, will X-rays fracture enough surrounding nuclei to
lead to lingering radioactive decay radiation that causes
environmental concerns?

Sorry to phrase it in environmental terms, but that's where all the
political controversy is. Politically, nobody seem to care if the
launch crew gets killed, just as long as there isn't some kind
lingering contamination for the general public to feel scared about.




But suppose some material or mechanism could be found to capture and
harness that X-ray energy for propulsive purposes. Wouldn't there be
an inherent amount X-ray exposure to the flight crew? Or could you
tailor the matter-antimatter anihilation to somehow minimize this?

I realize that if your magnetic bottle blinks and you lose the
magnetic containment, then your entire fuel supply will blow up in a
big X-ray burst, and there would be no hope of the flight crew
surviving. But if it only takes a few minutes to get up into space,
then your crew only has to be near the anti-matter for that short
period of time. And how much anti-matter would you really need, just
to get a Saturn-V type of payload into orbit?

Your crew would be sitting at the top of the Saturn-V sized rocket,
and the ittybitty quantity of anti-matter would be sitting all the way
at the bottom of it.

99% of the volume of the Saturn V is used
to store fuel. Your antimatter drive could have a specific
impulse 100 times better than a H2O2 rocket thus reducing
the volume of propellant needed to 1% of that of the
Saturn V

http://science.nasa.gov/newhome/head...p12apr99_1.htm

Keith

On Tue, 02 Nov 2004 16:00:38 +0100, John Thingstad
wrote:

On 1 Nov 2004 19:49:30 -0800, Eric Moore wrote:

(sanman) wrote in message
. com...
Damon Hill wrote in message
. 134...



What would you all recommend as a promising High-Energy Density
Material?

Well, there's always Anti-Matter:

http://www.navyseals.com/community/a...le.cfm?id=4614

Oh, just wonderful! Just what we need. A more powerful bomb..
Antimatter is a great source of energy if used intelligently.
In the hands of the military it can only spell death.
Still I suppose it was inevitable that the millitary would investigate
the possibility. Luckily so far antimatter has only been produced in
minuscule quantities. It is currently not a option either as a fuel
source or a weapon. Since antimatter is made from energy
you have to put more energy into making antimatter than you
are going to get out of it. Currently no one could produce enough
energy to produce a sizable quantity of the substance.
Or even if they could the price would be astronomical.
(I can envision something like giant coils put in the flux passage at IO
perhaps
or over the sun that could generate enough current to power a huge
accelerator
and produce large quantities. But that is just science fiction today.)


Where did you get the idea that it produces X-rays?
It would produce gamma rays!
Pretty much sterilizing the area down to the bacterial level for miles
around.

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