In Mr. Heinlein's cosmos, interplanetary rocket travel is old stuff. Earlier books got his characters to the moon and to stations parked in space. [In "Red Planet"] he describes colonial life on Mars some years after men from the earth have settled there. He even throws in a desperate revolt against dishonest agents of the operating company back on earth. When Jim and Frank, sons of colonials go to boarding school they take Willis, a Martian called a bouncer, about the size and shape of...