science

Maybe I could have been more explicit. Without the planetary alignment that made the voyager probes possible an equivalent mission would be ridiculously expensive/impossible due to the fuel requirements (and wouldn't be able to visit all of the planets)

If starship/new glen/the rocket lab one work, it might become more feasible.

Instead, sending smaller, simpler probes that just visit one planet/moon would be much more cost effective, but still expensive.

We have already got a lot of the low hanging planetary science fruit from existing missions. New missions would need new/novel sensors or need Landers/aircraft which make them much more expensive.

Even just a 'standard' interplanetary mission isn't just an out of the box job like current earth satalites are becoming.