It isn't that pinpointed, calculating and tracking the position of something in our solar system relative to earth to a few (hundred) thousand square kilometers

It isn't that pinpointed, calculating and tracking the position of something in our solar system relative to earth to a few (hundred) thousand square kilometers precision should be little problem. "For example, a typical Ka-band signal from Mars spreads so wide that when it reaches Earth the diameter of the energy is many times larger than the diameter of the Earth. A typical optical signal, however, will spread only over the equivalent of a small portion of the United States, requiring less energy use and waste." From http://www.nasa.gov/pdf/742122main_LCRDFactSheet3.pdf http://www.nasa.gov/pdf/742122main_LCRDFactSheet3.pdf