Now that Curiosity is safely on Mars and ready to begin its exploration, an exploration that could go on for decades due to its nuclear power plant, I would like to propose the next major NASA endeavor.
It is time to return to Jupiter. The Galileo mission (1995-2003) was a tremendous success even though the spacecraft was crippled by the loss of its high gain antenna. Some 90% of the potential data was lost due to the failure of this vital communication link.
It’s time to go back to Jupiter again. Only this time the mission will look more like the Cassini-Huygens mission to Saturn. The next Jupiter mission should include an orbiter to survey Jupiter and its moons. But this time let’s add a lander for Europa. Europa is the most promising venue for extraterrestrial life in the solar system. A rover on Europa could explore the ice floes and run tests on the surface materials. The reddish-brown gunk that emerges from the cracks in the ice floes and spreads across the surface of Europa may be a life form similar to an algae bloom. We need to go there to check it out. Also, the rover could measure the thickness of the ice. This step would be in preparation for a following mission that will melt its way through the ice to place a submarine into the ocean below.