what do we need to do before we send men back ?

A couple of things I came up with a

An orbiter to map the Moon in detail especially the poles. Many areas of the
Moon today are not mapped to 20 m resolution we can easily do 10m for the
entire moon and 1-2m for selected portions.

A follow on to Prospector getting a better idea of where the hydrogen is.

A radar map to give us a picture at depth of the Moons surface.

A couple of landers at potential base sites would be usefull.

What did I miss in my quick list?