[crystalmeph]

I don’t know exactly how fast the air currents at 40,000-60,000 feet will drive a balloon, but I would assume that this most recent balloon was already airborne by the time the previous one was discovered. As long as they don’t launch anymore starting last week, this particular episode should wind down peacefully.

As to why use balloons instead of satellites, the most reasonable speculation I’ve seen is that they’re collecting signals intelligence (radio traffic, etc.) which is not accessible from orbital distances.

[LarryMullins]

Large controllable balloons could probably be 'recalled' by instructing them to crash into the ocean. If any more big ones like the first balloon show up, it's probably on purpose.

[crystalmeph]

I was wondering why China wouldn’t include a self-destruct feature. My daughter pointed out that crashing into a US city, even unintentionally, would probably be seen as even more hostile than sending the balloon in the first place. You obviously could choose to self destruct in a remote area or over water, but they may well have considered the escalation risk to be too high if they added potentially destructive capabilities.

[singularity2001]

The hawaii balloon had ground measuring lasers