[Logic]

Originally Posted by freebeard

First time I've clicked on a Google link in a long, long time; they changed their format.

Oops: I fixed the link to go to:
https://www.newscientist.com/article...ound-to-space/

Originally Posted by freebeard

Probably Helium, but it could be steam.
www.researchgate.net: Advances in Steam Aerostation

Completely Off Topic but whatTH!

I have never even considered steam as a lifting gas!
Thx. That opens up a hole new rabbit hole!

IMHO Hydrogen is THE lifting gas.
Did you know the helium lobbyists added oxygen to their 'dangerous hydrogen' demo blimp before blowing politicians of their grandstand with it!?

NB: I'm not saying a manned, passenger carrying blimp should be filled with H2.
I see no future for blimps as passenger or even cargo carriers anyway:
It doesn't matter how safe you make them or how clever you are about not popping up like a cork when you offload your cargo; you are still at the mercy of the wind as to what direction you can travel in.
ie: With all that surface area for the wind to catch, their economical airspeeds are barely faster than a light breeze. So unless where you want to go happens to be downwind of where you are...

All the filmed demo flights share the same 'Not a breath of wind' one sees in 2 wheeled velomobile videos.

Originally Posted by freebeard

So why not a semi-rigid? The Plimp:

Egan Airships: The PLIMP™ Invention
But compare the maneuverability of the Roboloon:

At 1:06 watch it cut the propeller half way and coast to it's destination.

My interest is in ...erm... kites that don't drop to the ground when the wind stops blowing.
ie; The pictured method of semi rigid blimp construction, on a 'string'.


So when windless; it just bobs about like a party balloon on a string, but when the wind does blow you want the wind to impart lift so your 'party balloon on a sting' is not blown down to the ground.