If you want a more challenging project that takes shape with some real cutting and sanding, small manufacturer Semroc produces high-quality balsa rocket kit reproductions. The Mars Lander, originally sold by Estes in the 1970s, is a beautifully realistic-looking spacecraft with spring-loaded landing legs. You can also try their Saturn 1B ($78), a 1/70 scale re-creation of the Apollo booster.
