[MarkMc]

Hmm so a probe can't sling-shot around another planet to do a U-turn?

[kryptiskt]

It's possible, Parker Solar Probe is using Venus for gravity assists to get very close to the Sun. http://parkersolarprobe.jhuapl.edu/The-Mission/index.php

It will take 7 passes of Venus though.

The reason that PSP isn't taking these images despite going much closer is that it doesn't have a camera for imaging the Sun.