I did a brief test with the launcher. It takes 70% of the Pyra's Hull Armour, and 30% of the Permahull. Such, I assume it deals Pierce and perhaps some Shatter damage. I also noted a 5 stack of fire, but this is unconfirmed and highly unlikely.
On the topic of AoE, it is reckless to attempt to detonate the mines on purpose. The damage is substantial, and I suggest popping the balloon instead.