The European Space Agency’s next large mission will be JUICE, a probe to study Jupiter’s icy moons. People who study other areas of astrophysics (like me) are disappointed that ESA didn’t choose a mission to the stuff we’re terribly excited about. In particular, some people are very disappointed that the X-ray observatory ATHENA lost out.
The most striking thing to me is the extremely long time scale. JUICE isn’t scheduled to get to Jupiter until the 2030s. I know it’s sometimes necessary to plan way in advance, but it does seem like a big gamble to devote a bunch of resources to something that far off. How certain are we that the questions that seem interesting now will still seem interesting then?