What is the name of C.S. Lewis’s fictional planet-travel trilogy?

C.S. Lewis’s fictional planet-travel trilogy is called the Space Trilogy.

The series consists of Out of the Silent Planet, Perelandra, and That Hideous Strength. Its central character is Elwin Ransom, a philologist whose adventures take him from Earth to other worlds and into conflicts involving moral, spiritual, and technological forces.

The first novel, Out of the Silent Planet, was published in 1938. Perelandra followed in 1943, and That Hideous Strength appeared in 1945. Together, the books combine science fiction with Christian theology, classical ideas, and criticism of modern technocratic power.

Readers sometimes call the series the Ransom Trilogy because Ransom is its recurring protagonist. That informal name is understandable, but Space Trilogy is the widely recognized title for the group of novels. The trilogy is also distinct from The Chronicles of Narnia, which is Lewis’s children’s fantasy sequence set largely in the fictional world of Narnia.