Discoverable Launch Locations

New location discovered: Space

SimplePlanes has them and they're super fun, so why not SR2 as well?

Here's how they could work:
In Planet Studio, when a launch location is selected, it would have a switch toggle named Discoverable in the panel, similar to Visible In Map View and Flatten Terrain for structures. Enabling this would offer 2 modes - planet-based and location-based. I'll explain both of them.
For location based, this casts a sphere around the location's spot, very similar to the system editor's SOI markers. I'll call this sphere the "sphere of discovery" for now. It works how you'd expect, going into the SOD would unlock the launch location for you to use it.
Another thing is maybe allowing to use a cylinder or square/rectangular-shaped SOD, useful in some cases.
For spheres, the radius can be resized.
For cylinders, the diameter and height.
For squares, it can be resized (and rotated) on each axis, similar to the Local Scale/Rotation for sub-structures.

For planet-based discovery, the SOD of this can only be a sphere, of course. The "center" of the sphere is located at the center of the planet, essentially making the SOD a big force-field-like thing around the planet. Like the location-based SOD's, the sphere can be resized (especially useful for highly irregular-shaped asteroids with lots of jutty-out bits) although there could be a minimum of 1 meter above average ground level.
The actual discovery works just like how you'd expect; craft touch SOD, location gets added to the list, discovered locations would be listed below the permanent locations but above custom-saved ones, and of course can be deleted so that you can enjoy discovering it again, for whatever reason.