They can do an aerial backflip in half a second, accelerate at two Gs, and fly rotor blade to rotor blade in three-dimensional formations—and they do all this autonomously. We tell them where to go but not how to go. Each robot communicates with a network of motion-capture cameras mounted on the ceiling of the lab. The cameras are connected to a computer, which calculates the position of the robot and its neighbors. It's like GPS, but the information is updated 100 times per second with sub-centimeter accuracy. The robots also have sensors that measure angular velocity, accelerometers like those that tell airbags when to deploy, motors to run the propellers, and circuitry to control the motors and batteries.