Re: Electrogravitics is Reality!


tomcat wrote:
William.Mook@xxxxxxxxx wrote:
tomcat wrote:
William.Mook@xxxxxxxxx wrote:
Tomcat doesn't realize that SRBs are used to provide additional thrust
at launch, not provide the efficient increase in speed higher
performing cryogenics provide. lol.

But just for fun let's do the calculation.

Let's assume the proposed cockpit weighs the same as a Mercury capsule,
907.2 kg.

Now the SRBs Gross Mass: 589,670 kg. Empty Mass: 86,183 kg.
Propellants: Solid Thrust(vac): 1,174,713 kgf. Isp: 269 sec. Isp (sea
level): 237 sec. Burn time: 124 sec.

Wow!

So, tomcat wants to take 4 SRBs and burn them in PARALLEL!!!! (he talks
about SSTO so they're not staged which would give slightly better
performance) under an updated version of a Mercury capsule... OUCH!
The pilot better have a chiropractor... lol.

Take off weight of the four SRB + mercury cluster would be; (hold on
let me get my spreadhseet started...)

TAKE OFF BURN OUT
2,359,587.2 345,639.2 Weight
4,698,852 4,698,852 Thrust
1.99 13.59 GEE

That puppy would put out quite a kick!!!

The specific impulse is 237 sec max. That's an exhaust velocity of;

Ve = g0 * Isp = 9.37 * 237 = 2,327 m/sec

And propellant fraction is;

u = 0.8535

which isn't too shabby... so now we can compute the IDEAL terminal
velocity of this setup;

Vf = Ve * LN(1/(1-u)) = 2,327 * LN (1/(1-.8535)) = 4,470 m/sec

Which is about HALF the speed you need.

By the way, this is essentially the same performance as a single SRB
flying from liftoff to burnout all by itself;

1.992153238 Gees at take off
13.63044916 Gees at burnout
0.853845371 Propellant fraction

4475.68455 Terminal velocity


During ascent you'd likely lose about 1,500 m/sec to gravity losses
(its more like 2,200 m/sec normally but when pulling 14 gees you gain
some advantage) so actual performance would be around 3 km/sec. The
capsule would come crashing down a little downrange from the same spot
the SRBs come crashing down after a shuttle larunch today.

Of course you can do this suborbital flight much much better with a
redstone rocket, like Al Shepard did back in the early 1960s.

If you want to get to orbit with a single stage and a minimum capsule,
I'd recommend something like the Atlas Mercury rocket used by John
Glenn back in the early 1960s. That thing had 3 rocket engines at lift
off, it dropped two on the way up, and had one sustainer which got it
to orbit. It was a balloon tank pressurized by propellant, and worked
very well as a stage-and-a-half. But we could call it SSTO today. I
always liked the idea of recovering the engines for reuse. But that's
sort of what the Space Shuttle does today - except its much bigger, and
the throw away engines are SRBs.





Yes, that was a 'fun' calculation.

Yes.

But mathematics can be deceptive.




My last statement in the quote was "but mathematics can be deceptive."
Let me explain.


Lets not and say you did.


If you launch from near the equator towards the East then you will pick
up about 700 mph because of the Earth's rotation. That is not in the
Tsiolkovsky Equation.


That's because the rocket equation - which you have apparently looked
up on the internet and found is also called Tsiolkovsky Equation -
haha... speaks only of terminal velocity. All the other bull*** you
mention is just that. It doesn't change the need for speed.

Look, if I was given the longitude and latitude of New York City 40 d
45m 6s North and 73 d 39 m 59 s West - and Chicago, 41 d 52 m 28 s
North and 87 d 38 m 22 s I could compute a great circle route from one
city to the other. I could compute the distance of that arc to be
711.14 miles.

That would be the MINIMUM distance I'd have to travel to get from one
point to the other. Now, if I had a car that got no more than 28 miles
per gallon I'd be able to say I'd need at least 711.14 / 28 = 25.39
gallons of gas - as a minimum to drive from one city to the other in
that car and likely need more.

Now, if you came along and said by driving slower I can use less gas
than driving fast, I'd have to say how slow, because if the car just
sat still and idled, it wouldn't be going anywhere - and there's an
optimal speed, depending on gear, road condition and so forth. That
wouldn't change the MINIMUM amount of gas required, changing speeds
away from the optimal conditions INCREASES fuel use, so the minimum
will not be got around that way.

If you came along and said the car must travel on roads, and the car
can turn left and right, and that a car that tavels straight covers
more distance than a car that zig zags all over the place I'd have to
say that any deviation from the great circle route would increase miles
travelled and increase fuel use. So the minimum will not be got around
that way either.

If you came along and said that a car going uphill uses more gas than a
car going downhill and that if we travelled downwhill all the way we
could use less gas, I'd have to say Chicago and New York are on the
water, and are pretty much the same altitude, and any up and down the
hills will increase fuel use. So, the minimum will not be got around
that way either.

JESUS TOMCAT - people are trying to educate you a little bit here -
pick up a freakin book on the subject you post about and read it. Do
the exercises at the end of each chapter, and check it against the
answers in the back of the book. Re read the chapters until you get
the right answers and see why. Don't give up, rack your brains, read
related books at a libarary, talk to people who wrote the book - THAT'S
WHAT I DID WHEN I WAS IN SCHOOL STUDYING THIS ***!

You're supposedly a freakin military pilot with a degree? I don't see
it. Juding from your responses here you're a freakin' poser in over his
head - maybe you carried tools for someone who worked on a military
aircraft and dreamed about flying it - maybe that's what you did - but
judging by what you've written here - I don't see it dude.


The size of the vehicle is not in the Tsiolkovsky Equation.

Because the size of the vehicle doesn't determine the final velocity,

The fact that for every air mile traveled the Earth drops away at point
64 miles is not in the Tsiolkovsky Equation.

Because the properties of the earth don't determine the final velocity
of a rocket under ideal conditions.


The fact that gravity diminishes with the square of the distance is not
usually used in calculations.

Depends on which calculation you're doing. Every hear of
equipotential? Sheez


The fact that the Moon has 1/6th the gravity of Earth and this pulls on
the surface of the Earth when it is overhead is not normally in the
calculations.

Which calculation? You still talking about the rocket equation? If
so, the rocket equation gives the amount of propellant you need in a
rocket to make it go a given speed. Clearly the properies of the moon
don't determine the final velocity of a rocket propelled projectivel
under ideal conditions.



The length of the burn time is not in the Tsiolkovsky Equation.

Because in the absence of a gravity field, under ideal conditions, the
length of burn time does not determine the final velocity of a rocket
propelled projectile.


These are just a few of my objections to the calculations that I often
see.

They are objections that make no sense. They make no sense because its
like someone objecting that it'll take 25 gallons of gas at a minimum
to drive to Chicago from New York - and likely more given the great
circle distance and the gas mileage.

The rocket equation determines the speed of an rocket of a given ratio
of propellant to dry weight burning a propellant of a given specific
impulse under ideal conditions. We know under IDEAL CONDITIONS what
the MINIMUM speed is to get to orbit. This is the same as figuring out
the gas mileage of a car you plan to take a trip in. If you don't have
a minimum amount of gas, you ain't going to make the miminum distance
needed, See? Same here. If you don't have the right propellant
performance and propellant fractdion, you're not going to make it to
orbit. Your objections are senseless and reveal a deep seated ignorance
and foolishness.


The Earth dropping away combined with the length of the burn time
is an enormous factor.

This is secondary to the minimums. Once you've built a rocket that can
go the minimum speed, then you can talk about how to fly it. That's
another topic entirely.

If I said I had to drive 711 miles in a car that got at best 28 mph and
I said it only held 10 gallons of gas, then, I'd say I'd have to refill
the tank before I got to Chicago probably 2 times. That's entirely
different than which route I take, or what direction I head out of New
York when I leave. That you see a relation there just tells me you
don't understand what the word MINIMUM SPEED REQUIREMENT TO ORBIT
means.


Twenty minutes at, say, mach 3 in perfectly
level flight -- not relative to the Earth -- relative to the planes
orientation at time of takeoff would put that rocket plane at 480 miles
of altitude above the Earth -- with just 'level' flight!

Hmm... definitely don't know what equipotential means! lol. Dude,
you have a center of gravity for the earth right? And you have
spherical surfaces around that point that have the same energy see?
You're really a triple 9 mensa? Damn bitch, you don't know this ***?
lol.

THE SAME ENERGY BITCH! Does that suggest anything to you?

If you are on that equipotential surface, then you've only got drag to
contend with. If you rise to higher levels, you've got to get the
energy from somewhere, and if your engine is putting out constant
energy, then its going to come from your speed. If you fall to lower
levels, the energy has to go somewhere, and that's likely to go into
your speed. If you're rising and accelerating at the same time, you've
got to pump out enough energy to add to your potential energy AND your
kinetic energy. Fuckin around with wings and *** in an underpowered
aircraft just ADDS TO THE MINIMUM SPEED REQUIRED UNDER IDEAL
CONDITIONS.


It is clear,
therefore,

That you are clueless.

that the Tsiolkovsky Equation

Gives the relation between propellant performance, propellant
frraction, and terminal velocity of a rocket under ideal conditions.
Its one of the most useful equations in rocket science. It allows you
to compute the terminal velocity of a rocket propelled projectile under
ideal conditions. Its like figuring out the basic range of your car
given the gas mileage and amount of gas on board. Driving directions
don't enter into it.

and other orbital equations

What other equations? Dude, the great circle route between New York
and Chicago is the MINIMUM. The minimum bitch! Monkeying around with
driving directions and side trips and hanging flags out the windows -
means you need MORE GAS! lol.

simply do not include all the pertinent factors.

What is more pertinent in a rocket projectile than the MINIMUM SPEED
NEEDED TO PERFORM A MISSION?

Despite the insults,

Dude, if I take an hour and calculate the performance of a rocket that
you propose as a SSTO vehicle - and show CONCLUSIVELY that it CAN NEVER
attain orbit as you proposed it - how the hell is that an insult? The
insult bitch is putting up with your punk ass bull***.

I nonetheless, enjoyed the mathematics displayed

Too bad you didn't understand them.

in the William Mook post. Because of the mathematical discrepancies in
current use -- not picking on Mook here -- I have been loathe to use
the formulas.

Because you don't understand them.

Pilots know that thrust to weight tells a lot.

So what? You're still talking about side trips and have ignored the
basics. FYI The Brequet range equation in an aircraft, very similar to
the rocket equation, tells more.


And, by the way, take an ion engine with 20 thousandths of a single
pound of thrust and fill the rocket plane up with ion engine fuel and
Tsiolkovsky's Equation will give it escape velocity and then some.

Yeah, a radium powered rocket producing 1 millionth of a gee force
operating for 1600 years would accelerate some 45 km/sec - UNDER IDEAL
CONDITIONS - it would go nowhere under normal conditions because its
too puny to move itself.

There is something 'wrong' here.

Yeah, you're clueless. So, we shouldn't be surprised if you are
confused at times.

I say that such a plane would never
roll down the runway, much less get off the ground.

Well you got that one right genius. Jesus tomcat, you have no pride do
you? Weren't you the one arguing that 1.1 gees was just fine in a
space craft? And radium makes a dandy rocket?

***.

What's wrong is you don't get it. A rocket under ideal conditions can
have a very high terminal velocity. But that's not all you need. You
have to have sufficient thrust to overcome gravity without too much
loss. Use calculus of variations to figure out what the optimal thrust
is at lift off. For most rockets today its around 1.4 gees.

Your proposed saucer is underpowered for that reason.

But I am still contemplating all of this and will continue this
discussion later.

Like I said, call a college bookstore - one serving a good enginering
school like MIT - and ask for the reading list for the aeronautical
engineering degree program - and order the damn books. Read them, do
the exercises until you master them, and THEN post your ideas. Sheez.




tomcat

.