Air & Space/Smithsonian is a magazine for aerospace enthusiasts, and is an adjunct of the Smithsonian Institute’s National Air and Space Museum. Writing a department piece is one of the best ways of breaking into the magazine. This includes book reviews, which should be 200-450 words about a soon-to-be-released or recently released book, and reviews of videos, movies, aerospace-related recreational products, or software. They also publish other departments and in-depth features. They want queries, not complete articles. Rates vary, and they offer kill fees. Details here.