I really like the "mark" function in Celestia, but it is unfortunate that the green markings cannot be saved or connected. I think it would be very useful for some users to be able to create and save interplanetary/interstellar/intergalactic routes, mark different regions, make spatial maps, color spatial regions etc.. It would be nice to have some data about the "maps", for example the lengh of the route in parsecs or the number of stars (planets etc.) in marked spatial regions.
Is it possible? It would help to create some futuristic human science playground...
First of all: Welcome to the CelestialMatters (CM) forum!
As to your request/question: Such connected routes are certainly possible. Yet -- given the current smallness of our dev team, this feature can unfortunately not range very high up in our todo list.