Airship to Orbit [Was: Cities in the sky]

>
> As air pressure falls, you certainly get the benefit of increased
> insulation between the electrodes, thereby allowing higher working
> voltages - but the amount of "working fluid" for lift thrust quickly
> diminishes. I suspect any scaled-up lifter will be a low altitude craft
> only. More likely (and unlike blaze labs) I suspect /any/ scaled-up
> lifter will be unable to carry its own generator for independent flight.
>

I believe the exact opposite is true. In my recollection, old-style
high-flying piston aircraft (B-29s, TWA constellations, etc.) needed
special high-altitude magnetos that were sealed and pressurized, to keep
the charge from bleeding off to the point that it would not fire the plugs.
A neon bulb is evacuated to lower the resistance to the point where a few
hundred volts of potential will travel the multi-meter length of the tube
instead of the centimeter or so it would arc under sea-level air pressure.

Steve