Solaris is a 1972 Soviet psychological science fiction film based on Stanisław Lem's 1961 novel of the same title. The film was co-written and directed by Andrei Tarkovsky, and stars Donatas Banionis and Natalya Bondarchuk. The electronic music score was performed by Eduard Artemyev and the film also features a composition by J.S. Bach as its main theme. The plot centers on a space station orbiting the fictional planet Solaris, where a scientific mission has stalled because the skeleton crew of three scientists have fallen into emotional crises. Psychologist Kris Kelvin (Banionis) travels to the station to evaluate the situation, only to encounter the same mysterious phenomena as the others.