Activating one of these gives me a message about an abandoned starship that I can claim and repair. Most of the time, though, this isn't the case because there's an NPC there who has a task for me. Is there something different I can or should do to actually find a claimable ship? And why does it say there is one when there isn't?

And at times, the NPC wants me to build a communication station, which is never possible even though I have the blueprint and materials. What is the deal with this?

As I understand it, the locator is for a distress signal which can be a crashed ship with a pilot nearby or a crashed freighter as well as a crashed ship without a (living) pilot. So, thank the random number generator for your getting tails multiple times in a row.

However, also AIUI, if you search for distress signals in an abandoned system then none of the crashed ships will have pilots wating for rescue. The downside is that abandoned systems are always low tier economy systems, so there won't be any crashed S-class ships -- except for the very rare crashed exotic.

Thanks! Yep, I was fine with the multiple scenarios from the map... I just thought maybe I had an option to do something when they were telling me I was headed for a claimable ship. Now I know they're just messing with me :)

Any insight into the apparently impossible communication station thing?

I have occasionally had problems placing those, as well as things like the save beacon. Try moving yourself away from the area and then use the build camera to find a place near the crashed ship where can be built. If still having problems, try moving your ship ouit of the immedate vicinity. The game is sometimes flaky about where it allows things to be constructed.