> I'm not sure if your question is implying that you could float your way up to LEO altitude. I suspect you couldn't with anything that could be engineered.
Even if you could make it, I doubt it would work for very long.
Such a balloon would presumably be quite massive and probably impossible to maneuver. As such it would be a nice target for things that were actually in orbit (moving quite fast relative to it). It would probably become swiss cheese in the matter of days/weeks. (probably not a problem for the balloon itself I suppose, but I can't imagine anything you would be hanging from it would be happy with that.)
Even if you could make it, I doubt it would work for very long.
Such a balloon would presumably be quite massive and probably impossible to maneuver. As such it would be a nice target for things that were actually in orbit (moving quite fast relative to it). It would probably become swiss cheese in the matter of days/weeks. (probably not a problem for the balloon itself I suppose, but I can't imagine anything you would be hanging from it would be happy with that.)