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Old July 12th 06, 08:29 PM posted to rec.models.rockets,sci.space.history,sci.space.policy,rec.aviation.military
Brad Guth[_1_]
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wrote:
You've GOT to be kidding! lol. Is F=ma worn out too? hahaha...

This has GOT to be a joke. Really.

A disinformation tactic!? Those who know laugh, those who don't know
are confused or they actually believe the bull****.

sigh

ROCKET EQUATON

Figure out how fast a rocket stage will go knowing only the exhaust
speed of the rocket and the fraction of propellant.

Vf = Ve * LN(1/(1-u)) is still useful, despite your asinine
bull**** here.

Vf = final velocity of a rocket propelled projectile
Ve = exhaust velocity of the gases coming out of the engine
LN(..) = natural logarithm (base 'e')
u = propellant fractoin (a number between 0 (empty) and 1 (all
propellant)

Typical numbers;

ADVANCED ROCKETS
Solar/laser sail - infinity (no propellant)
Fusion pulse - 100,000 m/s
Ion - 50,000 m/s
Orion Nuclear Pulse -20,000 m/s (effective)
Nuclear thermal - 8,500 m/s

STATE OF ART ROCKETS
LOX/LH2 - 4,200 m/s
LOX/RP1 - 3,000 m/s
Hypergolic - 2,800 m/s
SRB - 2,200 m/s
H2O2 - 1,800 m/s
Nitrogen - 1,500 m/s

THRUST CALCULATION

F = mdot * Ve

F = thrust (Newtons)
mdot = mass flow rate
Ve = exhaust velocity


POWER CALCULATION

P = 1/2 * mdot * Ve^2

Power = watts
mdot = mass flow rate
Ve = exhaust velocity

FRACTIONS


1 = p + s + u

p = payload
s = structure
u = propellant

Typical values for s range from 0.08 to 0.22 depending on details like
thermal protection systems, and so forth.

THRUST TO WEIGHT

The thrust to weight of a typical chemical rocket is around 70 to 1.
That is for each pound or kg of mass you have 70 pounds or kgs of
thrust. But nuclear thermal rockets have a thrust to weight of about
20 to 1 at best. And nuclear pulse rockets like Orion are likely to
have a 5 to 1 thrust to weight. Ion rockets have 1/10,000 to 1 - they
cannot lift off earth. Fusion pulse rockets that have high performance
have very high captue of reaction products which means a very large
thrust structure, so they are likely not to have high thrust to weight.
Since no one has built these systems before there is a disagreement
about what they might achieve. Studies with thrust to weight from 2 to
1 down to 1/3 to 1 have been produced. The 2 to 1 can be used on
Earth. The 1/3 to 1 cannot, but can be used on the moon and mars.


Dear William Mook,
How totally pathetic, and how otherwise typically Jewish and Third
Reich collaborating of yourself.

Good grief, since we can't possibly get ourselves safely onto the moon
or much less that of mars is why that 1/3 to 1 argument is so
absolutely pathetic beyond any fly-by-rocket joke that can be imagined.
Going one-way via nuclear is however doable, and as such should be
applied.

Apparently a Mook moon intended rocket can be made of iron, as having a
inert GLOW of nearly 30% and still get it's 50+t payload past LL-1 in
hardly any time at all. Too bad your rocket-science can't be
replicated since nothing that's considerably newer and way better can't
seem to manage 80:1 (total rocket/payload ratio) for so much as a
one-way GSO ticket to ride, much less 60:1 for accomplishing such a
quick two-way ticket to/from our moon.

There's no question that your nuclear pumped rocket will accomplish the
task with energy and payloads to spare. However, that previously
mentioned 70:1 ratio is still rather pathetic if having to include each
of the multi-stage inert mass that has to go along for the ride,
whereas some of that liftoff and in route mass has to include spare
retrothrust fuel tonnage plus even a few unavoidable tones that simply
can't ever be fully utilized.

The only liquified rocket fuel, that we honestly know of, which offers
sufficient octane and thus the best possible fuel density and thus best
ISP is somewhat limited to that of your intellectual flatulence.
Therefore, gong fully nuclear is in fact a good solution that needs to
get accomplished before be run ourselves out of terrestrial energy
alternatives to the point where we can't even pull off a good WW-IV.
ADVANCED ROCKETS
Solar/laser sail - infinity (no propellant)
Fusion pulse - 100,000 m/s
Ion - 50,000 m/s
Orion Nuclear Pulse -20,000 m/s (effective)
Nuclear thermal - 8,500 m/s


STATE OF ART ROCKETS
LOX/LH2 - 4,200 m/s
LOX/RP1 - 3,000 m/s
Hypergolic - 2,800 m/s
SRB - 2,200 m/s
H2O2 - 1,800 m/s
Nitrogen - 1,500 m/s


What's nearly frozen/slush as 98% h2o2 along with c3h4o worth?
-
Brad Guth