What is the title of the first novel in C.S. Lewis's Space Trilogy?

The first novel in C.S. Lewis's Space Trilogy is Out of the Silent Planet.

Published in 1938, the novel introduces philologist Elwin Ransom, who is kidnapped and taken to Mars, called Malacandra by its inhabitants. The story combines planetary adventure with Christian and philosophical ideas, presenting a populated solar system rather than a hostile, empty space.

The trilogy continues with Perelandra, published in 1943, and concludes with That Hideous Strength, published in 1945. Although the three books share characters and themes, their settings and narrative styles differ substantially. Out of the Silent Planet is therefore the opening volume, not the middle or final book.

Lewis wrote the trilogy partly in conversation with science fiction traditions of his time. He disliked stories that treated space travel as automatically making humanity morally superior. The novel’s title refers to Earth, which other planetary beings view as spiritually damaged and “silent” in a significant sense.