Coming in at No. 3 on the "flagship" projects list: a mission to Uranus. Like the Cassini-Huygens mission to Saturn, the mission to Uranus would send a probe into the frosty giant's atmosphere while the orbiter begins its travels around the planet and its moons. The mission is projected to cost $2.7 billion. If that holds, and the two higher-priority missions don't break the bank, it's a "go." Otherwise, the panel says, it too should be redesigned as a less ambitious mission, or canceled.