This story was originally published by Knowable Magazine.

You hear a mechanical buzz. You look up, and there it is, hovering in the sky—four whirring rotors. Over your shoulder, you catch sight of someone tracking the flight and manipulating controls.

Drones, little flying vehicles with varying states of autonomy, have arrived. Some survey crops from above. Some film dazzling videos. Some just annoy the neighbors. In Virginia, drones have delivered library books. And NASA launched the Mars rover, Perseverance, on July 30, 2020, which features a helicopter named Ingenuity that will have to be somewhat autonomous because of the communication delay between Earth and Mars.

 …