This document presents a genetic algorithm approach for mission and safety planning with unmanned aerial vehicles (UAVs). It combines two existing genetic algorithm architectures - a hybrid genetic algorithm (HGA4m) for mission path planning and a multi-population genetic algorithm (MPGA4s) for replanning paths under critical situations. The proposed approach embeds both architectures into a single hardware system called MOSA (Mission Oriented Sensor Array) for mission supervision and IFA (In-Flight Awareness) for safety supervision. Computational results show the approach can find good solutions for both path planning and replanning within hardware limitations of onboard processors.