In this world, as soon as humans invent FTL, they launch "telescope-satellites" (I don't know what to call them) out in several directions. They travel at 10c, can communicate instantly with Earth, and are 10 meters in size (maybe bigger if someone gives me a reason for changing the size).
How many should be sent out? I'm currently thinking 6 but maybe there is a reason for more beyond just more is better.
What are the distances that they'd pause at to observe on their way out? They can't observe while traveling because the whole FTL thing would prevent it.
How far out would you want to limit them to? At some point you'd probably start getting diminishing results. For example the vertical ones would be outside of the galaxy long before the others. It seems that you probably wouldn't want/need to go past over 50,000 ly from the galactic plane because you could fairly easily image the galaxy as a whole at that point.