$64 Billion and seventeen years to land on the moon. What's wrong with this picture?

(Russell Wallace) wrote in message ...
On Mon, 15 Mar 2004 20:04:04 GMT, Eric Pederson
deZ to respond wrote:

The ultimate for a non-toxic, storable, moderate thrust system would be
spark or hot wire ignited NOX/alcohol.

I'm curious, why would alcohol be used instead of kerosene?

For long duration missions, there is a significant morale advantage
to the use of Nitrous Oxide/Ethanol-Sucrose mixtures.
If the system fails, you can at leaast have a dandy slap-up party
while you wait.

--
P. Stickney
(Ethanol-Sucrose no doubt diluted to 75.5%, as supplied by Bacardi)

(Old posting, but I've gotten behind on some of the major discussions...)

In article ,
Russell Wallace wrote:
The ultimate for a non-toxic, storable, moderate thrust system would be
spark or hot wire ignited NOX/alcohol.

I'm curious, why would alcohol be used instead of kerosene?

There are substantial advantages in volatile propellants which evaporate
easily and leave no residue behind. Whole classes of problems with
propellant residues in cooling passages, injectors, etc. go away.

Kerosene, unfortunately, is a complex and poorly-defined substance which
almost invariably has some non-volatile components. So there's an oily
residue left behind when it evaporates.

Alcohols, on the other hand, are easily available as pure substances.
If you wanted to minimize the legal hassles and the performance, not to
mention the rate of unexplained evaporation from closed containers :-),
you might use isopropanol rather than ethanol.
--
MOST launched 30 June; science observations running | Henry Spencer
since Oct; first surprises seen; papers pending. |

In article ,
(Henry Spencer) wrote:

not to
mention the rate of unexplained evaporation from closed containers :-)

Look, Henry made funny! :-) Imagine, engineers and scientists
ingesting the rocket fuel stocks . . .

--
Herb Schaltegger, B.S., J.D.
Reformed Aerospace Engineer
Columbia Loss FAQ:
http://www.io.com/~o_m/columbia_loss_faq_x.html

"Henry Spencer" wrote in message
...

There are substantial advantages in volatile propellants which evaporate
easily and leave no residue behind.

I was going to say something about the precise definition of 'storable' here
as it applies to volatile liquids, but decided I would let someone else do
that.

"Herb Schaltegger" wrote in message
...

Look, Henry made funny! :-) Imagine, engineers and scientists
ingesting the rocket fuel stocks . . .

Sittin' on the beach drinkin' rocket fuels oh yeah
Spendin' all night breakin' all the rules oh yeah

-- Cold Chisel, Cheap Wine

In article , says...
(Old posting, but I've gotten behind on some of the major discussions...)

In article ,
Russell Wallace wrote:
The ultimate for a non-toxic, storable, moderate thrust system would be
spark or hot wire ignited NOX/alcohol.

I'm curious, why would alcohol be used instead of kerosene?

There are substantial advantages in volatile propellants which evaporate
easily and leave no residue behind. Whole classes of problems with
propellant residues in cooling passages, injectors, etc. go away.

Kerosene, unfortunately, is a complex and poorly-defined substance which
almost invariably has some non-volatile components. So there's an oily
residue left behind when it evaporates.

Alcohols, on the other hand, are easily available as pure substances.
If you wanted to minimize the legal hassles and the performance, not to
mention the rate of unexplained evaporation from closed containers :-),
you might use isopropanol rather than ethanol.

I also think that he choice of alcohol vs. kerosene can have something
to do with availability. I know that in the case of the German
development of the A-4, the use of alcohol was mandated by the
relatively difficult access to petroleum-derived fuels in the Third
Reich. With Nazi Germnay's failure to take and hold the north African
oil fields and their military's ravenous thirst for gasoline and
airplane fuels, it became reasonable for them to select alcohol as a
fuel in any system where it was possible and reasonable to do so.
Alcohol could be (and was) created from all sorts of biomass, thus
removing the need for oil sources in its creation.

As I recall, the Germans also pioneered techniques for making gasoline-
like fuels without petroleum, for exactly the same reasons.

Doug

(Henry Spencer) wrote:

Kerosene, unfortunately, is a complex and poorly-defined substance which
almost invariably has some non-volatile components. So there's an oily
residue left behind when it evaporates.

Which suggests that you could specify a petroleum based fuel that was
composed of nothing but the volatile fractions.

D.
--
Touch-twice life. Eat. Drink. Laugh.

Herb Schaltegger wrote:

Look, Henry made funny! :-) Imagine, engineers and scientists
ingesting the rocket fuel stocks . . .


It happened more than once in the V-2 program; the Germans added
something to the alcohol that made it unpalatable. The cooling alcohol
for the MiG- 25 "Foxbat" also had a tendency to go missing (it was
injected into the intakes at full speed to keep the motors from melting)
shortly after one's arrival at a Soviet airfield- everyone loved it when
a Foxbat showed up.

Pat

In article ,
Derek Lyons wrote:
Kerosene, unfortunately, is a complex and poorly-defined substance which
almost invariably has some non-volatile components. So there's an oily
residue left behind when it evaporates.

Which suggests that you could specify a petroleum based fuel that was
composed of nothing but the volatile fractions.

Oh, you certainly can, but if you want kerosene's relatively low vapor
pressure (which is good for handling safety and storability over wide
temperature ranges) but a thorough absence of non-volatile components
(things with *really* low vapor pressures), my understanding is that
you're into the realm of "narrow-cut" fuels... which require complicated,
fussy purification and hence are relatively costly.

The alcohols have the advantage that they are synthesized and hence
inherently start out without a bunch of quite similar compounds
accompanying them.

If you're willing to live with high vapor pressure, of course, you can use
things like propane and butane, which are easily had in relatively pure
forms. Propane in particular is a very nice fuel for use with LOX -- it's
still liquid at LOX temperatures, and considerably denser that way.
--
MOST launched 30 June; science observations running | Henry Spencer
since Oct; first surprises seen; papers pending. |

In article ,
Neil Gerace wrote:
There are substantial advantages in volatile propellants which evaporate
easily and leave no residue behind.

I was going to say something about the precise definition of 'storable' here
as it applies to volatile liquids, but decided I would let someone else do
that.

"...the term `storable' is peculiar. It merely refers to the fact that
the liquid does not boil off when one has it in a bucket. To say that it
is easily storable is stretching a point, particularly with some of the
liquids considered." -- D.S. Carton

There are obviously shades of gray here, but a liquid can be quite willing
to evaporate completely given the chance, while still being happy to stay
put in a closed container.
--
MOST launched 30 June; science observations running | Henry Spencer
since Oct; first surprises seen; papers pending. |