Nothing on the market worth it's money will do that. Just go find a heavily padded backpack, and get as much bubble wrap as you can.
Anyway, what you could really do (and it would be neat!) is pad a sidebag and hook it on your bike as a saddlebag. Then rig up an electromagnet or a solenoid to drop the bag on the ground (which is much shorter than watching it fly!) in the event that your wheels suddenly stop (or you could rig it so it occurs when you leave the bike or something).