Here are some ways to approach this question:
* Counting by individual spacecraft: If you count each individual spacecraft that has visited another solar system object, then there have been over 100 missions. This includes flybys, orbiters, landers, and sample return missions.
* Counting by target: If you count each unique object visited, then there have been missions to over 30 different objects in our solar system, including planets, moons, asteroids, and comets.
* Counting by type of mission: You could also count missions based on their primary objective, such as flyby missions, orbiter missions, lander missions, or sample return missions. This would give you a different kind of breakdown.
For a comprehensive list of all US missions to other solar system objects, you can consult resources like:
* NASA's Planetary Missions webpage: This site provides a list of all past, present, and future planetary missions.
* Wikipedia's List of missions to other solar system objects: This list provides information on missions by various space agencies, including the US.
It's important to note that the number of missions is constantly growing as new missions are launched and planned.
