Security ... think about it!
Titan's gravitational tug on the spacecraft is Cassini's sole means of altering course and each Titan flyby provides an opportunity to go down many different paths. Each Titan flyby is not a fork in the road, but rather a Los Angeles style cloverleaf in terms of the dizzying number of possible destinations. Each flyby choice affects all downstream choices. So how did our current and future plans for the path of the Cassini spacecraft come to be? That's the question Dave Seal put to me since that's my job – I am a tour designer.