Measuring Altitude and Deploying Parachute

I meant balloon cushions for easy-break parts and to lower the overall density while increasing the plate area. Design for X G impacts and make sure that terminal velocity is less than delivers X G's.

Can you put the drone props on freewheel hubs? 4 unpowered windmilling props could be aimed to stabilize the drone up. If they could be aimed, some sort of steering could be worked out.

Are there any motor-generators with enough kick per gram for drone use? Use wind driving the props to put some power back.

I remember an Estes rocket that went into a spin to slow its fall. It worked, the rocket didn't break on touchdown. I've seen parachutes fail in a number of ways