Cheap, easy to handle fuels/oxidizers

However, until someone invests HEAVILY in Lox Valve R&D, it will never be
reliable. Frozen Lox valves are one of the most common causes of vehicle
flight failures in the entire history of rocketry.

If that were so, I wonder why the Air Products plant operating practically
next door to where I live has never had such problems - at least none with
catastrophic effects.

Jan

This is just a WAG but...

Maybe it's because none of their valves are any where near flight weight?

Ad Astra,

Captain Obvious


"Jan C. Vorbrüggen" wrote in message
...
However, until someone invests HEAVILY in Lox Valve R&D, it will never
be
reliable. Frozen Lox valves are one of the most common causes of vehicle
flight failures in the entire history of rocketry.

If that were so, I wonder why the Air Products plant operating practically
next door to where I live has never had such problems - at least none with
catastrophic effects.

Jan

spacr wrote:
Lox is clearly the way to go in terms of cost and performance.
However, until someone invests HEAVILY in Lox Valve R&D, it will
never be reliable.

That's caused by humidity. It is absolutely critical that the valve and
any gas/air in the valve be absolutely dry before passing LOX through it.

NASA don't seem to have many problems. NASA run, if I remember
correctly, nitrogen gas through their systems
for several hours before launch to dry the pipes out as part of the
chilldown procedure.

Frozen Lox valves are one of the most common causes of vehicle flight
failures in the entire history of rocketry.

That's more to do with the learning curve than anything else. It's a
subtle problem, even tiny amounts of moisture can produce rock hard ice
crystals- which are terrible for valve seatings. Additionally, moisture
can freeze out from the atmosphere and physically stop any external
mechanism from operating; again, the same technique of minimising the
moisture or controlling the temperature on the outside of the valve pays
dividends.

Jay Troetschel

I think that the safest amateur liquid bipropellant
fuel would be kerosene and laughing gas (N2O).

Both comonents are quite safe to store and easy to handle.
The preformance should be quite OK- Isp ~200 secs:-)

The disadvantage is that these components are not hypergolic ....

Maybe it's because none of their valves are any where near flight weight?

You mean you'd shave off a few grams but risk mission failure!?

Jan

Greg Pribush wrote:
I think that the safest amateur liquid bipropellant
fuel would be kerosene and laughing gas (N2O).

Both comonents are quite safe to store and easy to handle.
The preformance should be quite OK- Isp ~200 secs:-)

The disadvantage is that these components are not hypergolic ....

There's also 'party fuel', N2O + ethanol. Neither should be injested in
excessive quantity. Personally, I injest neither.

Dear John,

Sorry,
I'm not a teacher...
You are going to have to go down the learning curve on your own.
The fact that FMC was refusing to sell you H2O2 because you failed to grasp
even the fundamentals of the safe handling procedures for H2O2 should have
been a clue to you however.

Now your mixing H2O2 with hydrocarbons and you think having some H2O in the
mix is going to make every thing OK? Here is a freebie: in the 1960's the
Air Force did a study on H2O2 decomposition to see why the 98%H2O2 that they
had stored in drums for long term stability testing were still slowly
decomposing. What they found was that water is actually a low grade catalyst
for H2O2. They found that there was however a stable form of water which
didn't act as a catalyst with H2O2, of course it's even more epensive than
H2O2 but the non reactive form of water is Heavy Water. I'll leave it as a
study exercise for you to track down the original research and find out why
Heavy Water is non catalytic.

Lastly, here is a puzzle for you: Why is "1948 angstroms" your potential
best friend/worst enemy?

As Always,

Jay Troetschel

"John Carmack" wrote in message
om...
"spacr" wrote in message
news:%PF4b.241388$cF.77683@rwcrnsc53...
The problem with H2O2 is that there isn't anyone currently working with
the
stuff who has even the smallest clue what they are doing. John Carmack
and
his people could save them selves a world of hurt that they are setting
them
selves up for if only they would sit their asses down and review the
literature. John, your going to get someone killed with your ignorance.
..

Jay Troetschel


If you are going to post something inflamatory like that, it would be
a reasonable courtesy to actually provide some specifics about the
"literature" that is going to keep me from "getting someone killed".

I have reviewed quite a bit of literature on peroxide propulsion, but
I am always happy to see more. If you have personal copies of
anything I haven't read, I would gladly pay a duplication fee.

John Carmack
www.armadilloaerospace.com

"spacr" :

Dear John,

Sorry,
I'm not a teacher...

That is very self centered of you. First you make claims about how dangerous
peroxide is, but you don't want to back your claims with checkable facts or
help avoid pitfalls.

You are going to have to go down the learning curve on your own.

Well, if you ever read John's site it is clear he already has done a lot of
testing before hand, without more information about you I think it is
possible that he knows more about peroxide than you do. However John instead
of acting like a know-it-all is still willing to learn from anyone who has
useful information to teach him.

The fact that FMC was refusing to sell you H2O2 because you failed
to grasp even the fundamentals of the safe handling procedures for
H2O2 should have been a clue to you however.

No, it is just proof that it is too easy to sue someone who has the slightest
connection to an accident. FMC is not worried about John blowing himself, it
is worried that if there is an accident with a craft that John designed,
fueled up, and flew, that they would be sued also just because they supplied
the fuel.

Now your mixing H2O2 with hydrocarbons and you think having some H2O in the
mix is going to make every thing OK?

50% and greater water is not just a little. If 50% was so dangerous it would
not be sold over the counter. Notice John has no problem getting 50%
peroxide, it is getting rocket grade purity that FMC gives him a hassle.
Also he has already tested it for shock and has not gotten it to explode. I
really suggest you read his site more carefully.

Here is a freebie: in the 1960's the Air Force did a study on H2O2
decomposition to see why the 98%H2O2 that they had stored in drums
for long term stability testing were still slowly decomposing. What
they found was that water is actually a low grade catalyst for H2O2.

Do you have a URL for that? That infact does not match the Russian
experience with long term storage. Unless you think 1% loss per year is
important which again is silly because if you had read John's site carefully
you would see that he uses up the peroxide within weeks if not just days of
recieving a shipment.

Check out:
http://www.ee.surrey.ac.uk/SSC/H2O2CONF/mjeff.htm
http://www.ee.surrey.ac.uk/SSC/H2O2CONF/afrolov.htm

They found that there was however a stable form of water which
didn't act as a catalyst with H2O2, of course it's even more epensive than
H2O2 but the non reactive form of water is Heavy Water. I'll leave it as a
study exercise for you to track down the original research and find out why
Heavy Water is non catalytic.

Why us? You made the claim, and it is not in any peroxide paper I looked at.
Everything I have read says the cleaner the tanks and the higher the purity
of the peroxide the lower the decomposition. Keeping decomposition below 1%
per year is simple to do, and 1% per year does not matter if you are going to
use it within a few days.

Lastly, here is a puzzle for you: Why is "1948 angstroms" your potential
best friend/worst enemy?

Meaningless if you are refering to light decomposing peroxide. John like
most people working on peroxide rockets store it in Stainless Steel or
Aluminium tanks - no light.

Check out the bottom of:
http://www.h2o2.com/intro/properties/radiation.html

What make you think you are the only one to study peroxide? Atleast supply
some pointers to your claims, otherwise they are just hot air.

Earl Colby Pottinger

PS: A quick search on your name found hits on my own website's textbase.
http://webhome.idirect.com/~earlcp/messages/M1002.HTML
http://webhome.idirect.com/~earlcp/messages/M1126.HTML
http://webhome.idirect.com/~earlcp/M...l_01_1999.html search for Jay.

I believe your's is the plant that blew up. Just because you had problems
does not automaticly mean everyone else will. Remember, John does test a lot
before doing anything.

As Always,

Jay Troetschel

"John Carmack" wrote in message
om...
"spacr" wrote in message
news:%PF4b.241388$cF.77683@rwcrnsc53...
The problem with H2O2 is that there isn't anyone currently working
with the stuff who has even the smallest clue what they are doing.
John Carmack and his people could save them selves a world of hurt
that they are setting them selves up for if only they would sit
their asses down and review the literature. John, your going to get
someone killed with your ignorance.
..

Jay Troetschel

If you are going to post something inflamatory like that, it would be
a reasonable courtesy to actually provide some specifics about the
"literature" that is going to keep me from "getting someone killed".

I have reviewed quite a bit of literature on peroxide propulsion, but
I am always happy to see more. If you have personal copies of
anything I haven't read, I would gladly pay a duplication fee.

John Carmack
www.armadilloaerospace.com

--
I make public email sent to me! Hydrogen Peroxide Rockets, OpenBeos,
SerialTransfer 3.0, RAMDISK, BoatBuilding, DIY TabletPC. What happened to
the time? http://webhome.idirect.com/~earlcp

Vince Cate just reminded me that it's more than a bit after
mid-September, and in fact the thing I was waiting for
(FALCON selections) is over, and I didn't get one of the
awards so this isn't really immediately commercially
sensitive anymore.

In mid-August we wrote:
George William Herbert wrote:
Vincent Cate wrote:
(Henry Spencer) wrote:
N2O, nitrous oxide, is what I meant.
Its performance is better than you would think based on its small oxygen
content, because it also has quite significant stored energy.

The combination of Nitrous-Oxide(N2O) and Propane(C3H8) seems
interesting. It seems to have a high ISP. Both self pressurize, and
are relatively safe and easy to handle. At the URL below they say "an
ISP of 230 at sea level, 290 at high elevation". I have not verified
this, but if accurate, that is rather good. Anyone else have ISP
numbers?

It's rather bad by standards of 'good' propellants; upper stage
lox/kero engines can get upwards of 330 S ISP, and hydrazine/tetroxide
can get upwards of 320 S.

I think those numbers are accurate for a higher pressure
motor; for lower pressure motors things are correspondingly worse.

http://web.wt.net/~markgoll/rse3.htm

Somewhere I found that propane has a pressure of 124 PSI at 70° F. I
think Nitrous Oxide is about 750 PSI at room temp.

Get thee to a library (or $$ and Amazon) to a copy of
Matheson's Gas Handbook. Therin are many secrets of the
thermodynamics and gas behaviour world explained clearly
for all to see.

You're not grossly off, but precision is important.
Especially with people who think 1.25 is a fine safety
margin in a pressure vessel 8-P

Seems like we use
the N20 to cool the engine (since it has extra pressure) and run the
engine with just 124 PSI feeds. Or maybe a simple pump that uses some
of the extra pressure from the N2O to increase the pressure on the
propane.

Not needing separate tanks to pressurize the Nitrous-oxide or Propane
simplifies things a little.

As a guy who thinks the rocket only need to get to about 5 km/sec and
then tethers/ion-drives can do the rest, the N2O/Propane seems like it
has a high enough ISP and would be easier/safer than most
fuels/oxidizers.

But is this ISP of 290 seconds real? Can we get that at 100 PSI?

Not at 100 PSI. (and do you mean tank pressure or chamber pressure 8-)

After mid-september I will have some more detailed discussion
in this thread, but it's a bit proprietary right now.

Let me start with a few observations.

1) Low chamber pressure is not your enemy; it increases the
rocket engine bulk and mass, but does not decrease Isp at
altitude significantly (other than, it being a lot harder to
get very very large expansion ratio nozzles).

2) The specific impulse loss at low altitudes is annoying but
not catastrophic, even for chamber pressures down in the under-100 PSI
range for the rocket motor.

3) There is a difference between gauge and absolute pressure.
At very low pressures, the difference between PSIG (which is,
after all, what a pressure vessel will have to resist) and PSIA
(which is what matters for a number of other factors) is going
to be a useful engineering advantage.

4) At very low pressures, even really dumb ablators like spray-on
fiberglass or oak work just fine for ablative motor chamber liners.

5) If you have low Isp, stage early and often.

6) The vapor pressure of nitrous oxide at around -50 F is around 125 PSI,
and the vapor pressure of propane at around 70 F is around 125 PSI,
and both are self-pressurizing.

7) Low weight tanks for 125 PSI are *light*.


With those observations made, let me give a brief product
description of FALCON-RASER (FALCON-Retro Aerospace Self-pressurized
Expendable Rocket), our FALCON proposal...

FALCON-RASER is a 4-stage little dumb booster, all four stages
using nitrous/propane at tank pressures of around 125 PSIA.

Each stage had a stage to stage mass ratio of 4, giving a
gross vehicle mass ratio of 256 . The total 'payload' mass,
including actual payload and the electronics/GNC package,
was 2,580 lbs including some margin, and GLOW was around
660,000 lbs. I had not finalized the structural material
and mass, but of the candidates (initial set: 6061 as-welded
and post-weld heat-treated; 6013 as-welded and post-weld heat-treated)
all came in well below my notional masses, except 6061 as-welded
which is at 103% of the notional masses (and would be at
the notional mass with a very slight margins relaxation;
i was using 1.25 Fs to yield 1.60 Fs to UTS, much higher
than typical aerospace practice).

I have an engine / injector design which I intend to keep
proprietary for the time being, but which would have cost
very little to fabricate.

I believe I was able to keep the bill of materials for the
guidance and control system below $100,000, which would
hopefully mean that the total system cost would be under
$250,000.

Without giving away all my prices, with a very healthy gross
margin and a sort of liberal guess at range costs, my total
customer cost estimate was around $5m for a vehicle I think
will deliver upwards of 2,200 lbs to 200 NM LEO. And the next
size up was expected to cost about $15m for upwards of 8,800 lbs.

I am, among other things, looking for commercial funding for
this to go forwards outside the aegis of FALCON.
Development costs are estimated to be Really Low.
Not much more than seven digits.


-george william herbert

Vince Cate just reminded me that it's more than a bit after
mid-September, and in fact the thing I was waiting for
(FALCON selections) is over, and I didn't get one of the
awards so this isn't really immediately commercially
sensitive anymore.

In mid-August we wrote:
George William Herbert wrote:
Vincent Cate wrote:
(Henry Spencer) wrote:
N2O, nitrous oxide, is what I meant.
Its performance is better than you would think based on its small oxygen
content, because it also has quite significant stored energy.

The combination of Nitrous-Oxide(N2O) and Propane(C3H8) seems
interesting. It seems to have a high ISP. Both self pressurize, and
are relatively safe and easy to handle. At the URL below they say "an
ISP of 230 at sea level, 290 at high elevation". I have not verified
this, but if accurate, that is rather good. Anyone else have ISP
numbers?

It's rather bad by standards of 'good' propellants; upper stage
lox/kero engines can get upwards of 330 S ISP, and hydrazine/tetroxide
can get upwards of 320 S.

I think those numbers are accurate for a higher pressure
motor; for lower pressure motors things are correspondingly worse.

http://web.wt.net/~markgoll/rse3.htm

Somewhere I found that propane has a pressure of 124 PSI at 70° F. I
think Nitrous Oxide is about 750 PSI at room temp.

Get thee to a library (or $$ and Amazon) to a copy of
Matheson's Gas Handbook. Therin are many secrets of the
thermodynamics and gas behaviour world explained clearly
for all to see.

You're not grossly off, but precision is important.
Especially with people who think 1.25 is a fine safety
margin in a pressure vessel 8-P

Seems like we use
the N20 to cool the engine (since it has extra pressure) and run the
engine with just 124 PSI feeds. Or maybe a simple pump that uses some
of the extra pressure from the N2O to increase the pressure on the
propane.

Not needing separate tanks to pressurize the Nitrous-oxide or Propane
simplifies things a little.

As a guy who thinks the rocket only need to get to about 5 km/sec and
then tethers/ion-drives can do the rest, the N2O/Propane seems like it
has a high enough ISP and would be easier/safer than most
fuels/oxidizers.

But is this ISP of 290 seconds real? Can we get that at 100 PSI?

Not at 100 PSI. (and do you mean tank pressure or chamber pressure 8-)

After mid-september I will have some more detailed discussion
in this thread, but it's a bit proprietary right now.

Let me start with a few observations.

1) Low chamber pressure is not your enemy; it increases the
rocket engine bulk and mass, but does not decrease Isp at
altitude significantly (other than, it being a lot harder to
get very very large expansion ratio nozzles).

2) The specific impulse loss at low altitudes is annoying but
not catastrophic, even for chamber pressures down in the under-100 PSI
range for the rocket motor.

3) There is a difference between gauge and absolute pressure.
At very low pressures, the difference between PSIG (which is,
after all, what a pressure vessel will have to resist) and PSIA
(which is what matters for a number of other factors) is going
to be a useful engineering advantage.

4) At very low pressures, even really dumb ablators like spray-on
fiberglass or oak work just fine for ablative motor chamber liners.

5) If you have low Isp, stage early and often.

6) The vapor pressure of nitrous oxide at around -50 F is around 125 PSI,
and the vapor pressure of propane at around 70 F is around 125 PSI,
and both are self-pressurizing.

7) Low weight tanks for 125 PSI are *light*.


With those observations made, let me give a brief product
description of FALCON-RASER (FALCON-Retro Aerospace Self-pressurized
Expendable Rocket), our FALCON proposal...

FALCON-RASER is a 4-stage little dumb booster, all four stages
using nitrous/propane at tank pressures of around 125 PSIA.

Each stage had a stage to stage mass ratio of 4, giving a
gross vehicle mass ratio of 256 . The total 'payload' mass,
including actual payload and the electronics/GNC package,
was 2,580 lbs including some margin, and GLOW was around
660,000 lbs. I had not finalized the structural material
and mass, but of the candidates (initial set: 6061 as-welded
and post-weld heat-treated; 6013 as-welded and post-weld heat-treated)
all came in well below my notional masses, except 6061 as-welded
which is at 103% of the notional masses (and would be at
the notional mass with a very slight margins relaxation;
i was using 1.25 Fs to yield 1.60 Fs to UTS, much higher
than typical aerospace practice).

I have an engine / injector design which I intend to keep
proprietary for the time being, but which would have cost
very little to fabricate.

I believe I was able to keep the bill of materials for the
guidance and control system below $100,000, which would
hopefully mean that the total system cost would be under
$250,000.

Without giving away all my prices, with a very healthy gross
margin and a sort of liberal guess at range costs, my total
customer cost estimate was around $5m for a vehicle I think
will deliver upwards of 2,200 lbs to 200 NM LEO. And the next
size up was expected to cost about $15m for upwards of 8,800 lbs.

I am, among other things, looking for commercial funding for
this to go forwards outside the aegis of FALCON.
Development costs are estimated to be Really Low.
Not much more than seven digits.


-george william herbert