Which C.S. Lewis novel was published in 1938 as his first science-fiction book?

Out of the Silent Planet was C.S. Lewis’s first published science-fiction novel.

Published in 1938, Out of the Silent Planet follows the philologist Elwin Ransom after he is abducted and taken to Malacandra, a planet that readers gradually recognize as Mars. The novel combines space travel with linguistic speculation, moral philosophy, and a critique of modern colonial attitudes.

It is the first volume of Lewis’s Space Trilogy. Perelandra followed in 1943, and That Hideous Strength completed the sequence in 1945. The books are connected by their protagonist and ideas, but each has a different setting and tone.

Lewis wrote the novel partly in response to what he considered spiritually thin or pessimistic science fiction. His friendship with J.R.R. Tolkien helped encourage his interest in imaginative literature, and the two writers famously challenged each other to write works involving space travel and time travel.