Stanislaw Lem, a popular science fiction author whose works included “Solaris,” died yesterday in Krakow, Poland. He was 84.

Lem’s writings were translated from Polish into more than 40 other languages, including English, and have sold 27 million copies.

Lem’s best-known work, “Solaris” was adapted into films by director Andrei Tarkovsky in 1972 and, in 2002, by Steven Soderbergh the latter starring George Clooney and Natascha McElhone.

Set on a spaceship above a fictional planet, it features a psychologist meeting the likeness of a long-dead lover as he and the crew grapple with suppressed memories of lost loves.

Lem’s first important novel, “Hospital of the Transfiguration,” was censored by communist authorities for eight years before its release, in 1956, amid a thaw following the death of Soviet dictator Josef Stalin.

Other works include “The Invincible,” “The Cyberiad,” “His Master’s Voice,” “The Star Diaries,” “The Futurological Congress,” and “Tales of Prix the Pilot.”

While Lem was widely known as a writer of science fiction, his works were never simple tales of spaceships and light-sabers. Rather, he confronted moral and existential dilemmas inherent in new technology. While his books often took place in the future or in some alternate dimension, they were connected to contemporary politics, especially the totalitarian realities of Cold War Poland.

Lem was born into a Polish Jewish family on September 21, 1921, in Lviv, then a Polish city but now part of Ukraine.