[jacquesm]

This one is probably my favorite:

https://www.space.com/nasa-telescope-far-side-of-moon.html

Though I'm not sure if it will ever be built.

[mulmen]

Even if such a device never made an observation or discovery the experience of building it and making it operational would be worthwhile.

[Phrenzy]

I wonder if they have a list of craters already picked out.