The Air Force has been holding out on us. Over 50 years ago they developed a functional robot that stood over 26 feet high, could carry 2,000 pound loads, and punched right through concrete walls.
So why, 50 years later, does warfare not look like this?
Besides the obvious answer (the Air Force hates fun), it's because the "Beetle" was designed for just a few missions, all of which were eliminated before it was completed.
The 85-ton robot was ordered by the Air Force to provide a maintenance capability for their nuclear-powered bombers. The Beetle would have been used to change out nuclear materials, payloads, and irradiated parts on the bombers in situations where a normal mechanic or ordnance worker would be irradiated.
The cab of the Beetle housed a single driver behind one-foot-thick walls of lead lined with 1/2-inch steel plates. The materials cut the radioactive exposure of the driver to a 3,000th of ambient levels.
The bomber program was canceled. But the Beetle was undergoing its final stages of construction, so the Air Force finished and tested it.
It did alright in testing, accomplishing all of its major goals despite throwing a track during a pivot test and suffering problems with the air conditioner/filtration system.
The test report also notes the high level of maintenance required to keep the robot working, something a 1962 Popular Mechanics article also highlighted. The system was prone to leaks and short circuits, among other issues.
After testing, the Air Force allowed the Beetle and one of its support vehicles to be transferred to the Atomic Energy Commission and NASA to aid with a nuclear rocket program. But, that program was also canceled as scientists found better ways of creating chemical propellants for rockets and missiles.
So the Beetle found itself without a job and just disappeared. The Air Force has never said what happened to the giant robot. So while no one can prove they started a robot fighting league in the desert, no one can prove they didn't.