The Time Was Past

Saturn captures a rogue celestial object. Saturn's new moon has a diameter of 900 Km, yet its gravitational effect on the rings was that of an object 10 times as large. Eighteen years was a speck of time in the lifetime of the Saturn rings, yet they were already showing changes that a 200 mm reflector telescope with a good eyepiece on Earth can see.
The scientist of the world demand this anomaly be investigated and if possible, its orbit changed. The original mission to Mars is re-tasked. After years of rebuilding and adding to the Mars spacecraft in orbit, it is renamed Saturn 1. It is now the culmination of earths space technology.
The planned nine year mission does not go according to plan, or does it? Natural events create a unique situation and decisions made by the planners create havoc. Results will extend over a millennium into the future, or is into the past?