Sam Gunn, Unlimited

Bova ( Mars ) takes us on a trip to a part of the universe where the men are real men and the women are willing. Bova's latest is a kind of pastiche of stories about Sam Gunn: former NASA employee, astronaut, entrepreneur and interstellar rascal. When not hitting the sack in zero gravity with an evil seductress, he's out convincing Earthside moneybags to buy up interplanetary real estate. But although Sam is a swashbuckler, he is also politically correct (sort of): he befriends and goes into business with Malone, the first person to recover from AIDS. ``Sam could be a true friend, caring, understanding, bringing out the best in a man,'' Malone reminisces to Jade, a young journalist on Sam's trail. Her interviews with his pals and business partners form the structure of this space opera. Though Sam's shenanigans (such as getting drunk for days on the moon) are wild and often wacky, he remains engaging, if a bit glib. He seems light-years apart from the serious professionals Bova envisioned trailblazing Mars. Sam is too lively a hero to hear about second-hand. The question is, how will this hero, who ostensibly disappeared into a black hole, survive to a clearly intended sequel? (Oct.)