I was wondering how much hydrogen (or helium, if you know) gas it would take to lift 100 pounds? Anyone know how to figure this out? This is discounting the rigging and gas envelope.
How this relates to astronomy: Why haven't we ever tried to lift a launch vehicle to a very high altitude and then released it? With this we could even launch it directly on the equator. I would think that as the LTALV (Lighter Than Air Launch Vehicle) rose higher the chances of an accident with hydrogen would lessen as there would be less oxygen to combust with.
How might the lifting values of hydrogen/helium increase or decrease in a thicker or thinner atmosphere (Venus, Mars)?