One year after Mars Express' arrival at Mars, the mighty rules of celestial mechanics have again set Christmas as the date for a major ESA event in deep space.
At 1.25 billion km from Earth, after a 7-year journey through the Solar system, ESA's Huygens probe is about to separate from the Cassini orbiter to enter a ballistic trajectory toward Titan, the largest and most mysterious moon of Saturn, in order to dive into its atmosphere on 14 January. This will be the first man-made object to explore in-situ this unique environment, whose chemistry is assumed to be very similar to that of the early Earth just before life began, 3.8 billion years ago.
My office-mate has been working on some of the last minute dynamics analysis for the Cassini-Huygens separation. Sometimes, the shear distance Cassini has traveled sets me back - fully an order of magnitude longer in travel time than the Mars rovers, nearly seven years to arrival. And she's working pretty darn well, too!