For example, you might want to prototype a soccer ball size micro-spacecraft that navigates around space station, looking for leaks in its hull. You might focus on the path planning problem, evaluating a variety of the path planning algorithms such as PLR, or you might try different approaches to reactive control, such as Brooks Subsumption architecture or Jim Firby's Raps system. This is even more risky than reimplementation, particularly if you plan on integrating with a real system. Using a simulator is much safer, but still risky. This is beyond the call of duty.
Caution is advised, along with especially clear and modest goals.
On the other hand, if you succeed this can be extremely rewarding. Once you come up with an idea I might be able to suggest places where you can get code or additional papers. This description draws extensively from a similar description by Professor Patrick Winston, which he uses for his excellent graduate AI course.