Operating drones low above ground and in complex terrain represents unique challenges, as most drone controls are limited to line of sight and uninterrupted satellite-based navigation. To endure in a GNSS-contested environment and operate indoors or underground, standard drones would not operate in such conditions. The drone platforms specially designed for subterranean or indoor environments require unique networking, sensing, navigation, and controls to enable such operations. Since these missions are complex and the drones are small, they are used in mission-specific roles such as autonomous mappers, FPV-operated lead elements, and armed effectors.