The Space Studies Board released their recommendations for the mission options for the next New Frontiers mission Announcement of Opportunity, due out in June. They recommended a wide-variety of missions highlighted in the Decadal Survey from a few years ago including: Lunar South Pole-Aiken Basin Sample Return, Venus In Situ Explorer, Comet Surface Sample Return, Network Science (a multi-lander mission to either Venus, Mercury, the Moon, or Mars), Trojan/Centaur Reconnaissance, Asteroid Rover/Sample Return, Ganymede Observer, and drum-roll please, an Io Observer. Nice to see that an Io Observer is still at least among the top eight missions for its class.
It, however, still won't happen this time around due to the restriction placed on the program by the lack of available plutonium for RTGs or nuclear-electric propulsion sytems (only enough currently for the Mars Science Laboratory, the next Discovery mission, and the next Flagship mission to the outer solar system). I do like the addition by the study group of "Innovative Mission Ideas", basically suggesting to NASA that the New Frontiers AO be as open as possible to all types of (preferably non-Mars) missions that fit within the cost cap.
The link to the report is below. Just click on "Read this book online, free." Thanks to Bruce Moomaw for the tip.
ADDED: I should note that Pamela over at Astronomy Cast Live posted on that blog that Jim Green, the Director of the Planetary Science Division at NASA, stated during a meeting either last night or tonight, that the New Frontiers AO will be open to all missions except to Earth and the Sun that fit within the budget and power source constraints. Preference will be given to those proposals that fit within those nine mission profiles mentioned above. Now, we just need to figure a way to do an Io Observer mission with solar panels (and not fry them in the process...).
ADDED: Quick correction. The SSB recommended a Trojan Asteroid/Centaur reconnaissance mission, not a sample return.
Link: Opening New Frontiers in Space: Choices for the Next New Frontiers Announcement of Opportunity [www.nap.edu]