cutemonster parent
How much do/can they use their own thrusters to change/correct their directions? I'm guessing it's just fractions of a degree? And needs to be extremely precise, done weeks? before reaching the next planet to slingshot around?
The Voyager probes were built with many course corrections and maneuvers in mind. They carried 100kg of Hydrazine fuel at launch, and it is almost all used up. That was about 1/8th of total craft mass at launch, which is significant.
Midcourse corrections are a standard and planned part of lots of probe missions.
I think we even did midcourse corrections for the moon missions.
A few degrees is probably the order of magnitude, though I haven't seen hard numbers.