I set a course as far from the nearest Commonwealth planet as I could and still stay within our fuel limitations. We ran across three star systems along our route, and we stopped to examine each. We had no equipment for long-distance sensing; I had to estimate by intuition what each world was like—and some of my decisions weren’t popular with my fellows.
The first system was easy to discard. I made a rough calculation of the star’s energy output and, from that, computed the band of habitability within which a planet might have comfortable enough temperatures for us to survive. There were two planets within that band, but both were small and practically airless, somewhere between Mars and Mercury in livability. Nobody wanted to stay there.
The second system we visited had two eligible pla
