There are a lot of challenging problem areas: rendezvous with small bodies (very irregular gravity fields), mission trajectory design, operations planning for flybys in the presence of, say, camera pointing constraints.
(@lutusp knows this already -- I'm putting it here just for interest.)
http://ssd.jpl.nasa.gov
Here's a snapshot of object locations in the inner solar system:
http://ssd.jpl.nasa.gov/?ss_inner
There are a lot of challenging problem areas: rendezvous with small bodies (very irregular gravity fields), mission trajectory design, operations planning for flybys in the presence of, say, camera pointing constraints.
(@lutusp knows this already -- I'm putting it here just for interest.)