In Allen Steele's parallel universe, at least, we enter worlds of technical credibility and believable characters depicting how humankind's early steps into solar system exploration and colonization might evolve into a fully spacefaring civilization. Robert Anson Heinlein and Dimension X for the 21st century on the way to starflight. Dreams matter. After all, everything that exists in the man-made world must exist first in someone's imagination. And Steele's depiction of our species' climb from Earth's gravity well with near term technology, with all our fallibility, feels so true in these alternate history interlinked stories that I often lost myself in their reality. How terrific albeit rare these days to read science fiction based on real science, with empathic human stories that don't end in the usual dystopian tragedy for Homo sapiens that too often characterizes SF today. We have a future in the cosmos, it seems. Dream on, Allen. . .