Lecture DescriptionThis paper describes the first time a fly-sized robot -- the Harvard Robobee -- has carried a sensor onboard. In previous flights, the vehicle was "flying blind" -- it required an array of external cameras to precisely track its trajectory to control its flight. In this paper, we used a light sensor inspired by the ocelli of insects to tell the vehicle about its motion relative to a light source so that it could stay upright in flight. It will be necessary for the fly to carry sensors like this for it to be able to fly autonomously. Additionally, we used our work to suggest a hypothesis about insect flight. Because our vehicle has similar size and dynamics to that of the honeybee, we suggest an explanation for how this animal could use its light sensing ocelli to fly stably without tumbling to the ground, which is currently an open question in biology. Sawyer B. Fuller, Michael Karpelson, Andrea Censi, Kevin Ma, and Robert Wood.