The polynomials are an end result of thousands of complex calculations. For more details, see http://ipnpr.jpl.nasa.gov/progress_report/42-196/196C.pdf . Many effects, including general relativity and the gravitational perturbations of the planets and several hundred asteroids, were included.
I hadn't heard of that. Just looked it up. I see you can go to http://ssd.jpl.nasa.gov/horizons.cgi and set the object to Pluto to see where it is which is kinda cool.
"Calculations on where Voyager was headed were plotted each day on graph paper posted on the wall at JPL. Soon the dots left the centre of the paper and began to wander onto the wall and then overhead. “There were dots on the ceiling for years afterward,” Owen says."
> “You can’t tell whether it’s small and close or big and far,” says Fran Bagenal, a space physicist and mission co-investigator at the University of Colorado Boulder. “It’s a really interesting problem that we’ve never had at any other planet.”
telnet horizons.jpl.nasa.gov 6775
Thanks, NASA!