The Invincible by Stanislaw Lem / ISBN 9780262538473 / paperback from MIT Press. I'm glad MIT Press brought some Lem back into print in nice editions.
A space cruiser, in search of its sister ship, encounters beings descended from self-replicating machines.
In the grand tradition of H. G. Wells and Jules Verne, Stanisław Lem's The Invincible tells the story of a space cruiser sent to an obscure planet to determine the fate of a sister spaceship whose communication with Earth has abruptly ceased. Landing on the planet Regis III, navigator Rohan and his crew discover a form of life that has apparently evolved from autonomous, self-replicating machines—perhaps the survivors of a “robot war.” Rohan and his men are forced to confront the classic quandary: what course of action can humanity take once it has reached the limits of its knowledge? In The Invincible, Lem has his characters confront the inexplicable and the bizarre: the problem that lies just beyond analytical reach.
Stanisław Lem (1921–2006), a writer called “worthy of the Nobel Prize” by the New York Times, was an internationally renowned author of novels, short stories, literary criticism, and philosophical essays. His books have been translated into forty-four languages and have sold more than thirty million copies.