I had the privilege of attending the public viewing at the Johns Hopkins Applied Physics Lab (thanks Kate!) and learned a lot about Messenger as it moved into the next phase of its mission. The design featured a range of ingenious bits of engineering to overcome weight limits, conserve fuel to push it into orbit, and to generally keep costs down due to competition from other NASA programs.
I'm a bit envious, as my field is international relations and for all the gee whiz tech that goes into defense I spend more time reading about cost overruns and projects that try to do too much and fail. Of course the bigger issue is that for anything political, the level of challenge Messenger achieved is just unthinkable. The metaphor they gave tonight was having to shoot an arrow from Miami to Seattle with a margin of error of less than the width of the arrow shaft. In politics, my rule of thumb is that any solution must be robust versus being implemented with some notable flaw;, if your idea requires hitting a bulls-eye at 20 paces, you should probably find a way to expand your target.
That said, tonight the international relations field has an important success and a failure of sorts that may save many lives. More on those after the cut.