Explorer-II Image Two
Two sonde coils generate magnetic fields that allow operators to detect the robot's location so it can be retrieved if the system fails.
A suite of onboard computers, controlled by the robot's two 32-bit nerve centers, direct an array of essential functions, including steering, video processing, leg expansion and retraction, and wireless communication.
Packed tightly inside the robot's power modules, the batteries allow inspections to last eight hours or moreâvery important given the thousands of miles of pipeline that need to be vetted on a yearly basis. A crew equipped with a single Explorer-II could inspect as much as two miles in a day.