So, not really on-topic, but this is probably the most likely place
I can look for leads. For reasons I'm not free to go into, I'm doing a
deep dive into how large high-altitude (50-70k ft) balloons are
constructed, both methods and materials. And I'm having a devil of a
time finding *anything* at all -- it doesn't seem like anyone's being
*secretive,* as such, but more that those "in the know" just don't talk
about it much. Even the NASA technical reports server came up empty --
lots of papers about *using* balloons, but not a single one about how
the ballons are *made*. Maybe I'm just failing to use the right search
keywords, but when I've simply searched for "balloon" and then checked
every single resulting paper....
So, given the crossover interest in using high-altitude balloons as
ersatz first stages for launch systems, I'm hoping that some list
members might have some knowledgeable advice on where I should go digging.
