Re: rocket question

On Sun, 16 Oct 2005 13:13:52 -0700, Eric <nospam@xxxxxxxxx> wrote:

>I accidently posted this in the wrong group (was looking at one group
>thinking i was looking at another) so I'll repost it here:
>
>Its my understanding that you need a 3 stage rocket to get to orbit. How
>small can a rocket be and still be able to accomplish inserting a small
>object (say, a 1 pound object for arguments sake) into earth orbit.
>Do all orbits eventually decay? Or is there some magic sped/alt where it
>becomes a permanent orbit?
>Thanks
>Eric


It's all based on the amount of thrust you get from the fuel compared to the
weight of the fuel and it's container and systems...

Right now, we don't have a fuel that can weigh so little that it can get to
space, but we do have systems capable of 2-stage operation.

Don't forget that payload weight, and height of orbit, is a big part of this as
well... since you only want 1 pound at minimal height, you might even break the
1 stage boundary!

I don't have the formulas here, but you basically want to get a fuel
package/motor to 18,000 mph, maybe you could figure it out... gravity will
remain about the same up to the 250 miles you need... dropping to about 97% or
so... so you need to know the motor thrust and fuel weight!

I'd guess with today's tech. it would be the size of a V2...

As for your orbit questions - define permanent? All orbits decay, when depends
on friction of space particles, sunlight pressure, and tide effects.

There is no 'magic speed', speed simply determines the diameter of the orbit.

.

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