Why should they burst? Certainly a little rubber balloon will - but the difference between a good helium balloon and vacuum isn't much - a thin foil layer would contain it without bursting.
The bursting is a fairly good automatic cut-down. If it doesn't burst, it will ceiling at some point, and then zoom around until something happens.
You might get some more height with a stronger balloon (or a larger balloon with less gas) but you want the flight to be over in a reasonable time if you ever want to get the payload back.
So then you have to use nichrome wire or something as a cutdown, just something else to worry about. 100k-ft is pretty good.
You might get some more height with a stronger balloon (or a larger balloon with less gas) but you want the flight to be over in a reasonable time if you ever want to get the payload back.
So then you have to use nichrome wire or something as a cutdown, just something else to worry about. 100k-ft is pretty good.