Re: Launch Technology

From: Spike Jones (
Date: Sun Jan 21 2001 - 00:15:26 MST

> > > "Ross A. Finlayson" wrote:
> >
> > Exactly what kind of rocket can acheive the necessary thrust to reach
> > orbit on less than fifty pounds of possible reaction mass/fuel
> > (including the engine)?
> Adrian Tymes wrote: A fifty pound rocket? ^_^;;;
> ge (~9000 m/s for standard Low Earth Orbit)
> Ve = exhaust velocity (~4500 m/s for standard explosive fuel)
> ...
> This would probably have to be solid fuels to make the non-consumed
> part of the engine less than 7 pounds.

Hmmm... Solid fuels dont provide the ~4500 m/s you quoted. The
4500 number applies to about the best liquid combination, lox and H2,
in vacuum. Starting with a 50 pound rocket, I have some *serious*
doubts we could make it to orbit with 7 pounds. I might believe
7 ounces however.

Ross, if you have a serious interest in rocketry, get up to speed
on the equations. They really are not as complicated as the
term rocket science implies. In fact rocketry is one of those
few fields where everything really is pretty straightforward,
not mysterious, and everything has already been worked out.

For a good estimate of what can be done, look at what
*has* been done. Look up on the web the Saturn V, for
instance, see how much mass it started with and how much
made it to orbit. Look up Orbital Sciences, Pegasus rocket,
see its mass and how much it can carry to orbit, recalling that
it is captive carried on an airplane. Look up Atlas Centaur.
Educate yourself as much as possible. You have a device
of unimaginable power right before you, the web. Use it.

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