Ben Bova's Venus. [Summary from inside flap of hardcover]:
The surface of Venus is the most hellish place in the solar system. The ground is hot enough to melt aluminum. The air pressure is so high it has crushed spacecraft landers as though they were tin cans. The sky is perpetually covered with clouds of sulfuric acid. The atmosphere is a choking mixture of carbon dioxide and poisonous gases. This is where Van Humphries must go. Or die trying. Late in the twenty-first century, Van is the sickly, fearful second son of a tyrannical corporate tycoon. His older brother perished years before in the first attempt to land a man on Venus, and his father has always hated Van for surviving when his brother died. Now his father is offering a ten-billion-dollar prize to the first person to land on Venus and return his son's remains. To everyone's surprise, Van takes up the offer. A socialite who has never done anything more strenuous than star on Princeton's debating team, he will launch a second attempt to land on Venus's ghastly surface, putting his own life at maximum risk. But meanwhile, another expedition sets forth to claim the prize - one organized in secret by the man Van's father fears most. What Van Humphrie will find on Venus will change everything - our understanding of Venus, of global warming on Earth, and his knowledge of who he is...