Thanks! I think it came out very well . It's interesting to do this kind of research too - to me this is what SF is all about, taking an idea (in this case, "what if were limited to 7.7 ly routes to the nearest stars?") and seeing where that takes you.

Astrosynthesis is a fiddly program to set up the way I want it, but once mastered it can be quite powerful. I guess I'm the ideal audience for it - a technically minded person who has some programming experience and who really wants to get it to do the stuff he wants done .

Anyone who is interested in more general mapping of the stars near Sol should really take a look at my Stellar Mapping page - it has accurate databases for the Solar Neighbourhood (out to 300ly distant) taken from the RECONS, DENSE and Hipparcos star catalogues! The data is presented as generic CSV files that contain either Galactic XYZ coordinates (usable for any purpose), or Astrosynthesis XYZ coordinates (specifically for importing in to AS only).