From: ansible@typhoon.xnet.com
Anvil wrote:
>Andrew wrote:
>> It seems that the helicopter must have two sets
>> of propellers: small ones for the troposphere
>> and big ones for the stratosphere. Perhaps the
>> best design is made of three propellers: one big
>> propeller placed between two small propellers
>> which counter the torque produced by the big
>> propeller.
Yikes. Now you've really complicated the design.
If you have rockets on the rotor tips, you don't have much torque on
the fuselage which then needs to be countered.
>You will want to research articles on Rotary Rocket and
>Hiller Helicopters. Consider that the air-breathing Hiller
>will outperform the use of just hydrogen peroxide and was
>itself of limited use.
You will also want to review the news archives for Armadillo Aerospace.
They tried peroxide rocket tips on helicopter blades too.
They had some interesting failures.
At any rate...
You need to remember that getting up in altitude is only a fraction of
the problem. You are using most of your delta-V to get to orbital velocity.
The most efficient way to do that is to get _out_ of the atmosphere as
soon as you can. Sticking around inside the atmosphere means drag,
which leads to heat, which causes all kinds of problems.
Better to get out of the atmosphere, and accelerate to orbital speed
there. So you need a rocket anyway.
And since you're designing rockets, you might as well design a big dumb
booster for the first stage, to keep the design as simple as possible.
There have been a lot of people with a lot of ideas, but I have yet to
see the practicality of anything other than a rocket.
There are some secondary advantages to having something like a carrier
aircraft take you aloft, but these have to do with launch site location
and other factors. 50,000 ft of altitude doesn't really buy you much.
James Graves
--- SoupGate-Win32 v1.05
* Origin: you cannot sedate... all the things you hate (1:229/2)
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