The Grand Master (both of them!) at his best. Spider Robinson did a fantastic job fleshing out RAH's outline – Variable Star has the spirit and flavor of the best of Heinlein's work. I was a little worried at the first couple of chapters; they were good sci-fi, but the contemporary references were a bit jarring. But soon enough I was totally immersed in a true Heinlein universe. The book was quite deftly inserted into Heinlein's Future History timeline, with a chilling reference to current events bringing about the election of Nehemiah Scudder. If you're a hardcore Heinlein fan, it's…