iPad Survives Fall From Edge of Space in Jaw-Dropping Video
space.com
space.com
An iPad 2 weighs 1.33 lbs, and has ~0.5 sq. ft of surface area when flat, which according to this NASA applet [1] means its terminal velocity is 12.2 mph (17.8 ft/sec).
A drop at 12 miles per hour onto its back is probably not enough to destroy the iPad whether or not there is a case on it.
Also - it kind of reminds me of a geek-version of the "bow and arrow" game from the film "Grown Ups"...
They need to stay away from airports and populated areas, also launch during the day and when there isn't cloud cover that would hide the balloon.
See here: http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&rgn...
Perhaps: iPad [with padding] Survives Fall From Edge of Space in Jaw-Dropping Video