SPEAKING OF STARS, and space, and extraterrestrial intelligences, the hottest thing in this whole hot summer (besides the looting in the big New York blackout) is, of course, Star Wars. Not only is the film a giant hit, but everything connected with it, and that includes the paperback book and all its tie-ins. With the admirable prescience that has made her if not the leading science-fiction editor, then certainly one of the top three, Judy-Lynn Del Rey bought Star Wars when it was still a twinkling asteroid, back in December of 1975. Now Del Rey Books (a separate entity under the Ballantine Books umbrella) has Star Wars moving up every paperback best-seller list in the country, and has gone back to press so many times that they are breaking records. (What distinguishes the book from so many other movie tie-ins is that George Lucas, the creator of the film, wrote the book himself and it bears the stamp of his creativity.) But when you have a winning horse you ride it all the way. Del Rey now has in the works: a Star Wars calendar, a Star Wars portfolio of prints suitable for scotch-taping to freshly painted walls: a Star Wars sketchbook of the costumes and the art: a Star Wars art book which is a complete collection of all the art from the movie (and not to be confused with the sketchbook) and (it goes without saying) The Making of Star Wars, which will appear in hardcover as well as paperback. What we have here is an industry, and if Judy-Lynn ever wants to go public and sell shares, I'd invest in her and Star Wars with my last spacey quarter.