Rio Tinto might be using automated trucks in iron mines in Australia but a rock in space is significantly farther away. Planetary Resources plans to mine platinum and water from these asteroids. The platinum is to make money when shipped back to earth. The water is for rocket fuel. The hydrogen and oxygen will be broken down into their component elements and used for propulsion. I don't know what methods they intend to use to break down the water or where they are going to get the power to do so but the ability to have reserves of rocket fuel on the asteroid being mined is pretty cool.
The company compares mining in outer space with drilling for oil on the ocean floor. It is true that complex mechanical activities do go on miles beneath the surface of the ocean, but when something breaks down you have to haul it the two miles to the ocean surface in order to fix it. What do you do when your haul truck breaks down on an asteroid hundreds of thousands of miles away or which only passes near earth every few years?