We present a methodology that enables a quadrotor aerial robot to autonomously explore single- or multi- floor indoor environments without any human interaction.The quadrotor is purchased from ascending technologies. It comes with an IMU and low level attitude stabilization. We outfitted the robot with a laser scanner, Microsoft Kinect sensor, and deflective mirrors to create a fully autonomous platform. We developed a navigation system that enables realtime localization, mapping, planning and control of the robot in confined indoor environments. All computations are done onboard the 1.6GHz atom processor with no requirements of external infrastructure. The exploration algorithm interacts with the planner and controller and provides continuous guidance to the robot.