[extropy-chat] balloon stations at the edge of space

[Dan Clemmensen]

Eugen Leitl wrote:

>On Mon, May 24, 2004 at 09:45:18PM -0700, Johnius wrote:
>
>  
>
>>  This thread reminds me of an invention of Win Wenger's
>>that uses balloons to suspend a mass-driver for cheap
>>space launches.  It occurs to me that several of you might
>>have some great feedback about the idea...
>>What do y'all think?
>>    
>>
>
>It sounds like a really good idea... until you do the math, and realize that
>LEO energy is all not about height, but about horizontal velocity component.
>And that goes with 0.5*m*v^2.
>
>So a ramp and a maglev stage (or a hypersonic airbreathing scramjet stage)
>brings you much, much closer to LEO than any stratospheric balloon.
>
>Latter have their own uses, though.
>
>  
>

If the idea works vertically, it should also work horizontally. Start 
with a series of
vertically-oriented mass driver balloons to get the payload into the 
stratosphere at
low velocity, Then pass to a mostly horizontal series of mass driver 
balloons to
generate horizontal velocity. As with any mass driver system, the 
vehicle must add
an additional horizontal component after it gets high enough, to move to 
an orbit that
does not intersect the exit point of the mass driver. When the exit 
point is in an atmosphere,
this acceleration must be higher than the atmosphere, also.

Of course, each balloon/driver will be accelerated back and down to 
conserve momentum,
so it will need to recover its original position between launches.

My guess is that the capital cost of this system is high. The minimum 
theoretical running cost
is quite low, however.

Given a horizontal mass driver suspended in the stratosphere with 
balloons,it might be more economical
to lift the payloads to the insertion end of the driver using balloons 
to provide buoyant lift, rather than
supporting a vertical mass driver.