The Invincible is a science fiction novel written by Stanislaw Lem in 1964.
Warning: Wikipedia contains spoilers
A spacecraft, called The Invincible for its high military potential, lands on a planet to investigate the loss of another spacecraft, of an identical model. During the investigation, the crew finds evidence of a new form of life, born through evolution of small machines. The novel turns into an analysis of the relationship between different life domains, and their place in the universe.