Doctor Doom developed this device early in his career, and found a chance to test it during his second encounter with Spider-man in Doom's hidden laboratory at New York City. The machine included metallic spheres orbitting a magnetical core. The balls were virtually unstoppable and presented a real threat when approaching an enemy. Spider-man disabled the machine by covering the core with web, thus nullifying the power source of the spheres. The spheres fell harmlessly to the floor… except because later Spider-man tripped on the balls and fell, giving the advantage to Doom. Doom was forced to retreat from the fight just at that point.
In Other Universes
In this universe, Doctor Doom also uses the (unnamed) Satellite Machine in his first encounter with Spider-man. Like in Earth-616, Spider-man understands that the attacking spheres orbit a core and covers it with web, making the balls fall harmlessly. Unlike in Earth-616, Spider-man never trips on the immobile balls.