Pure hydrogen H2 does not burn. To burn it must be mixed with O2. In a weather balloon, if you used pure hydrogen, the volume of gas you’d need would be 1/5 the volume of helium and a similar sized balloon would have five times the lift capacity with H2 hydrogen. If you lit a match inside pure hydrogen nothing would happen.

On the Hindenburg airship, they used hydrogen and you could not build such an airship of that lift capacity today without hydrogen. Choosing hydrogen and being careful would make balloon transportation with zero emissions feasible. If you used the polar jet stream, you could deliver and transport goods in 1/4 the time and with zero emissions.

In ww1 they used hydrogen balloons for observation. Accidents were few and even if you fired a tracer round through it nothing would happen.

On the supposed Chinese spy balloon, this was a hydrogen balloon. It made all the way across the world without incident. Judging by the size of it and how it was instrumented, I’d say it was a scientific instrument.

They already have it in the US and thanks to the news cycle we’ve already forgotten about it. How about that spy balloon? How come the US had stopped taking about it. What was on it?