[simonebrunozzi]

It seems that H2 is much more flammable compared to He.

I remember reading that someone was trying to use Aerogel as a substitute. Or a special version of it.

[I_Am_Nous]

Aerogel with CO2 is pretty common, I wonder if helium aerogel will be viable, or if the helium would slowly escape like it does in a balloon? I don't think we could use hydrogen for it as supercritical hydrogen sounds very dangerous.