The simplicity of the basics of mechanical engineering and rocket propulsion
is untaught and rarely discerned in 2009.

On May 25, 1961, JFK told us to go to the Moon.
On July 20, 1969, we landed on the Moon.
The job took 9.16 years starting from scratch.

1961 TECHNOLOGY STATUS:
Jet aircraft were starting to come into commercial use.
In 1966, NBC became the only color TV network.
In 1969, there were no push-button phones, fax machines, integrated circuits, "chips", LCDs, personal computers, or hand calculators. Mechanical desk calculators could only add, subtract, multiply, and divide.
A room-size IBM computer used punch-card input and printed-paper output
and had the power of a 386.
Most engineering calculations were made with a slide rule which gave 3 significant figures and no decimal point. Engineering in the 1960's was simple.

ENGINEERING DIMINSIONS:
In all of mechanical engineering there are only 4 basic dimensions.
The 4 dimensions are Distance, Force, Time, and Temperature.

UNITS OF MEASUREMENT (Pardon my English units from the 60's):
The basic dimensions of Distance, Force, Time, and Temperature
need only to have units of Feet, Pounds, Seconds, and degrees F.

A conversion table may have 1,000 conversion factors, but every variable from "acres" to "watt-hours" can be expressed in units of Feet, Pounds, Seconds, and degrees F.
A thousand conversion factors are unnecessary.

There is nothing in mechanical engineering and rocket propulsion that cannot be expressed in units of Feet, Pounds, Seconds, and degrees F.
If these units (and only these units) are used, formulas and equations become simple to verify by dimensional analysis, and common error sources are eliminated.
Many variables would be expressed in decimal fractions, which are awkward in conversation, but not for computer calculations.

The above is true for the metric system, which needs only units of
Meters, Newtons, Seconds, and degrees C to measure anything.

Note: Mass is not a dimension. Mass does not need a name or a unique unit of measurement. Mass is simply the weight of something on Earth divided by the gravitational acceleration on Earth per Newton's equation F = ma.
Thus, m = W pounds / 32.2 foot/sec^2 = pound-sec^2 / foot.
Simply use Weight in pounds divided by 32.2 to get Mass.

ENERGY, HEAT, and WORK:
These all have units of Foot-Pounds. Work is Force applied over a Distance.
There are always energy losses when energy is changed from one form to another. Even without friction and heat losses, there is additional unavailable energy
when heat is converted into work.
The unavailable energy (entropy) of the universe always increases.

POWER:
Power is the rate of energy, heat, and work.
Power has units of foot-pounds / second.

CONSERVATION OF MECHANICAL ENERGY:
In a closed system, the total of all forms of mechanical energy remains constant. The mass within a closed system can contain heat energy due to temperature (F), potential energy due to elevation (Feet), and kinetic energy due to speed (Feet/Second). All the forms of energy can change from one form to another,
but the total energy remains constant.

CHEMICAL ENERGY AND ROCKET PROPELLANT:
Most rocket propellant contains chemical energy which provides the heat energy
to accelerate its own mass to a supersonic speed producing rocket thrust.

Monopropellant such as N2H4 disassociates into N2 and H2 plus heat.

Bipropellant such as cryogenic liquid H2 and O2 combine into H20 plus heat.
H2 is the fuel and O2 is the oxidizer.

Solid propellant such as (NH4)2S2O8 (oxidizer} held together with a plastic binder and aluminum fibers (fuel) combine to form products of combustion plus heat.

PRODUCTS OF COMBUSTION:
The molecular weights of H2 (2) and O2 (32) indicate that 2 pounds of H2 combine with 16 pounds of O2 to form 18 pounds of H2O. One pound of rocket fuel requires 8 pounds of oxidizer to form 9 pounds of high temperature propellant gas.

ROCKET THRUST:
Google rocket thrust and you may find a complicated mathematical definition.
Think about rocket thrust and it is simply the unbalanced rocket chamber pressure times the nozzle throat area... F pounds = (Pc pounds / foot^2)( At foot^2).
If a supersonic (divergent) nozzle is used to accelerate and expand the exhaust gas to the ambient static pressure, an additional 40% increase in thrust is achieved.
This is called the Thrust Coefficient, Cf. Thus, F = (Pc)(At)(Cf) pounds.

PROPELLANT EFFECTIVENESS:
Propellant effectiveness is measured by its Specific Impulse (Isp).
Specific Impulse = (rocket thrust) / (pounds propellant / second).
Thus, Isp = (pounds) / (pounds / second) = seconds.

PROPELLANT IMPETUS:
Propellant Impetus is the measured Work that a pound of propellant can perform.
In 1252, Friar Roger Bacon of England wrote an essay describing the Chinese formula for gunpowder. By 1600, cannon were perfected to the point where few changes were made for 300 years. During that time, fixed fortifications realized
that it was necessary to test the impetus of their gunpowder in order to calculate
range vs. elevation for their cannon as follows...

A small vertical mortar was located beside a tall pole graduated in feet.
A measured weight of gunpowder propelled a measured weight of cannon ball
up along the pole. The person assigned to "keep your eye on the ball"
recorded the height of the ball (gunpowder Impetus) in feet.

But I digress.

Can Sub-Surface Moon Ice (-230C) Provide Rocket Propulsion?

I would like someone from from NASA to explain exactly how.

James T. Conklin, P.E.

That was a long and rambling post for a simple question that you could have looked up yourself.



Ice = water

Water = H20

Liquid oxygen and liquid hydrogen are used in the space shuttle and various other rockets, particularly in the upper stages.

H = Hydrogen
0 = Oxygen

Do you really need someone from NASA to explain this?

I read this post once and just skipped it because I didn't have a clue.

Suddenly it occurs to me that just a couple months ago, people were discussing whether moon water would be abundant enough not to have to ship it at extreme cost from Earth.

Now you want to burn it as fuel? I don't know how much ice is projected to be available on the moon at this point, but my guess would be that it is still scarce enough that you'd really have to conserve it for basic living necessities like drinking and growing food.

Luckily someone came up with a way to shower using sound waves. Hmmm, wonder why I haven't heard anything about that since going green became popular?

THANK YOU RobDegraves! TOGETHER WE CAN DO THIS!

All that is needed to produce cryogenic liquid hydrogen fuel
plus 8-times its weight of cryogenic liquid oxygen oxidizer
ON THE MOON; to be used as exothermic rocket propellant
from dirty, sub-surface, polar Moon-Ice at -230C (-382F)...

Is my patented Mk 2 Mod 4 portable, compact, light-weight,
free-standing, catalytic, solid-phase-water disassociater;
plus the appropriate transfer pumps and liquid storage tanks.

Sheesh.. if it's hard it's impossible?

1. You pointed out it's cold on the Moon... so cryogenic won't be so tough to do.

2. Extracting largely depends on where it is and in what concentration. That remains to be seen.

3. You need water and you need energy. If you are willing to go nuclear it's not that hard.


To be honest, I don't see the point of all this. It's theoretically possible so it can be done. However, whether it will be done is subject to a thousand variables including cost, benefit and political desire.


Did you actually have a point?

CAN LIQUID HYDROGEN & LIQUID OXYGEN BE PRODUCED FROM MOON-ICE?

RobDegraves justifiably dismissed using the catalytic water disassociater.
Although the Mk 2 Mod 4 solid-phase water disassociater was a complete failure
during initial demonstration tests on neat water-ice at 0C, it is anticipated that
performance will be worse on ice crystals entrapped in Moon rocks at -230C.

RobDegraves advocates that we "go nuclear it's not that hard".
I assume that Degraves' approach is to fly a nuclear reactor to the Moon
to disassociate ice crystals into cryogenic liquid hydrogen and liquid oxygen
using "heat energy" as he stated above.

I t should be noted that the initial testing using the Chernobyl nuclear reactor
resulted in the conversion of the neat water reactor coolant into high-pressure
super-heated steam which exploded the containment vessel and resulted in
the catastrophic melt-down of the nuclear reactor core.

It became obvious at that time that water cannot be disassociated with
"heat energy" from a nuclear reactor.

From an engineering standpoint, the answer to the question is: NO!

So... science.. have you ever heard of it?

The first principle is... you can't just make stuff up.



Didn't Marvin the Martian have something like that?

Other than that.. I have no idea what you are talking about.

QUOTE

Mk 2 Mod 4 solid-phase water disassociater