All Drone upgrades and Ship upgrades have a chance of breaking during a mission or after the mission is completed. The chance of the upgrade breaking gets higher the more the upgrades are used. Ship and Drone upgrades will have a small yellow exclamation point " ! " next to the upgrade to indicate to the player that the upgrade has a chance of breaking. Two exclamation means that the upgrade has a higher chance of breaking.
When an upgrade breaks, at the end of mission when it gives you a summary of your mission, it will say "[name of upgrade] has ceased functioning" in a red text, which means that the upgrade can no longer be used.
Bug: Ship Upgrades won't show if they have broken or not.