I've previously noted the Japanese Hayabusa probe that was sent out to retrieve samples from an asteroid. It turns out LEGO is going to be making an official set (available in Japan only, though, I believe) of this probe.
This is part of the LEGO Cuusoo project, that was piloted in Japan but is now coming to the internet near you. People can submit ideas and then vote on what they'd like to see LEGO produce as a set. I'm not 100% sure, but I think that LEGO designers take the original idea and rework it into a set, rather than simply taking submitted designs. Anyway, the previously noted Shinkai 6500 ocean probe was also produced via LEGO Cuusoo. Interesting that the first two projects that came through this program were science themed. I believe that these may have been prototype designs.