High altitude aerodynamics and propultion

herpamad

Been reading up on all this, and the problem you state has not really been implemented about stabalizing the payload and camera as i can find. And i can see any that have any type of propultion system, does any one know different?

Would seem that the rules about sending one up are pretty lax too, as long as the payload is under a value and the volume of helium is under another value, not yet found these values for the UK, but cant see them been too different to USA and Canada.

Balloons dont seem to have propultion systems, where as blimps and the likes do. I am guessing this is because a balloon is not as aerodynamic as a blimp.

Is a high altitude blimp going to be harder to achieve than using a simple balloon shape?

Been reading up on blimps, and would seem they use an airbag so when the helium expands the air dispands.

I am trying to figure out that if you let helium out before the burst point so the burst is avoided, how much higher the balloon can go before loss of boyancy. Is there any formulas for this or would one need to be created?

Thanks again for the help.

Antonio978

At their altitude the aerodynamics is not the first matter because de density of the air is very low. About the propulsion system the solar power could be an idea, especially if the UAV is provided with a wide span wing.