1: Prefab asteroid base; 2 construction built from modular space station kit; 3: combined exterior set; 4: original module from kit; 5: modded module; 6: prefab space station; 7: prefab interior.
Sometime you have to make a location yourself. The above two sets were constructed by modding prefab space stations.
The WarBug Asteroid Space Station (1) was a cheap prop which I liked, but it needed more. After a search I found the SkyLife SPACE modular skybox building system. I constructed the top section (2) and linked it to create a complete outside set (3). The interior shots were done on a couple of modules from the same set (4), but with the addition of prims around each to block the windows (5). Furniture and other props were added later.
D'Olby's base is another prefab called the Incognito space station (6). This was also fairly cheap, however it was constructed in such a way that none of the individual bits were linked as such. If you left it in your sandbox afterwards you'd get 20-40 returned objects (all called "object"). While that would be OK for a single shoot, it made it awkward to come back and do repeated shots. The interior had a certain amount of furniture (7), but I rezzed the space station several times, and edited almost everything, linking blocks of components together (but none with scripts in them) and renaming items like the doors and their controls. I now have a more flexible set of building blocks for interior shots in the next part).