[ExI] scieceblind

[Adrian Tymes]

On Fri, Oct 13, 2017 at 9:40 AM, Mike Dougherty <msd001 at gmail.com> wrote:
> Have we figured out how to fill a balloon with near-enough to nothing at all
> to make a lighter than helium balloon?
>
> I know the structural requirement for a large volume of empty space is
> considerable in Earth atmosphere.  I've been curious about the use of
> aerogels with enough crush-resistance to make lighter-than air craft
> literally filled with nothing - which would be cheaper and much safer than
> the only [non-]thing with more lifting power than helium (see: Hindenberg).
> I mean sure, worse case scenario your balloon fills with environmental air
> and crashes to the ground wouldn't exactly be a good time but at least you
> wouldn't also be exploding and burning on the way to the impact.

Aerogels aren't stiff enough.  When the air presses on them and
there's nothing behind them, they'd simply collapse to fill up that
nothing, and then you'd just have a solid mass of aerogel.

I happen to have a theoretical formulation that could do a vacuum
balloon, which has withstood all the theoretical analyses I've
subjected it to (from myself, and other engineers I trust under NDA;
any aerospace or mechanical engineers on this list who would like to
review it, please contact me offlist and I'll get you an NDA).  I've
been trying to find an airship manufacturer or the like who'd be
interested in prototyping and licensing the design.

> I was also wondering if you could tether enough of these together to
> encircle the globe, if you could hoist objects from this floating platform
> and literally throw them into space.

There's been some thought put into this concept.  Look up "orbital
ring" - or, on a far lesser scale (just one balloon), "rockoon".