Books in the Walter and Willy series

A funny book about friends helping friends, creative problem solving . . . and traveling through space. For astronauts ages 5 years and up.Up, up, and away! Willy wants to become the first piggy in outer space. But how? With Walter's help, of course. They try several ideas, but nothing works. Not even a trampoline! Then, with a wish and some imagination, the friends decide to build their own rocket ship.