there are tiny chip size wireless receivers for small distances like this, you would need some sort of window through the metal, or a tiny antenna inserted through the ball shell and the wireless covers just the inside

or just ultra-thin wires connecting the memory to the outside. the ultra-thin wire will just snap and it's too light to cause damage by whipping around

the big problem is kinetic impact, fire/fuel/water would be easy to solve, for example fire requires oxygen which will have difficulties getting inside through a tiny hole, and I'm sure there is some metal alloy which doesn't melt in typical plane fuel fire temperatures