Autonomous systems such as drones and self-driving cars are quickly entering human-dominated fields and becoming tangible technologies that will impact the human experience. However, as these systems share space and operate among humans, safety and reliability of autonomous systems become primary concerns. An important challenge for safety and reliability in autonomous systems is coping with uncertainty. This project focuses on three important forms of uncertainty: (1) noisy data from sensors, (2) asynchrony of distributed computation, and (3) heuristic computation of decision-making software. They bring various challenges for developing and validating software modules of autonomous systems.