For the longest time, I thought the following icon meant that your destination was a planetary surface:
But recently I saw two missions with the same destination in Olwain, and one had the icon while the other didn't (Kira / 20 Tourists):
The destination is not a planetary landing site:
So what does this icon mean? I'm thinking now that it indicates something about the Horizons expansion, but why would only one of these missions need it, and just for a run to a space station? Does it indicate that maybe the passenger will demand a new landing site that might be planet-side?