Traveling from my house to Downtown Los Angeles can be a mission, to put it mildly. So, before setting off, I input the destination into my iPhone. Apple Maps will quickly download GPS data, pinpoint my location and then give me a few route options. Assuming the 101 freeway isn't a parking lot, I'll set off, with Apple Maps' soothing female voice guiding the way.
In this scenario, repeated millions of times around the world, we often have seamless access to GPS satellites (providing location information) and data networks that overlay traffic, weather and other information services that, usually, make our road trips more intelligent. (Having said that, I always have a good old fashioned paper map in the glove compartment should I lose network connection or a solar flare knock out a GPS satellite. You never know.)
But say if you're planning an interplanetary road trip? How would your spaceship know what route to take? How would you orientate yourself in three-dimensional space when you're millions of miles from the nearest rest stop?