The night after the collapse, the geologists still wanted to look into the deepest throat of the new sinkhole, just beyond the white Corvette, the 1,000,000th. They carefully positioned some lights to shine down into that part of the hole and we flew the quadrotor as close as we could to get a good look. The look at 1:38 is the "money shot". When Jason Polk (WKU karst geologist) saw that, he knew that the hole had grown as far in that direction as it could. The heavy bedrock over the open dome told him that.
The other thing to notice in this flight is the quadrotor swinging around quite a bit. The clearest example of this is right after takeoff, but it happens again near the deepest point of the flight. Our pilot is not hotdogging or experimenting here; there were a lot of new air currents. "I'm getting some weird feedback here" is how Will described it. The cave was "breathing" differently after dark.
The quadrotor was piloted by mechanical engineers Will Johnson and Zach Lancaster, while the on-board camera was operated by Darren Tinker and Jesse Reesor. Professor Joel Lenoir and engineering technician Troy Robertson provided technical support and safety consulting. Troy Robertson shot the auxiliary footage on his iPhone.