It’s kind of hard to top last year. We had the trip to Pluto and Ceres all packed into one year and two missions. This year we still have some pretty great stuff going on. First, is the Juno mission to Jupiter. It actually launched in 2011, but will arrive on Independence Day and spend 20 months studying the gravity and magnetic fields. A big question it will attempt to answer is whether or not Jupiter has a solid core.
Meanwhile we also have the Mars Insight probe launching in March. It should land sometime in September with the express purpose of drilling a hole, about 16 feet deep to study heat flow and thermal history. It might even provide insights into the wobbling orbit of the planet.