Falha mecânica causou mau funcionamento no casulo de Jim e o acordou.
De wikipedia ,
The Avalon, a sleeper ship transporting 5,000 colonists and 258 crew members in hibernation pods, is on course to the planet Homestead II, a journey taking 120 years. Thirty years into its journey, the ship passes through an asteroid field, leading to a collision that causes a malfunction. The malfunction awakens one passenger, mechanical engineer Jim Preston, 90 years too early.
Outro POV que encontrei no Quora ,
As I understood it from the end of the movie, the opening scene represented an encounter with an asteroid field that overwhelmed it's defensive capabilities. The “deflector dish/asteroid destroyer” device could keep up with the smaller pieces, but was unable to stop a large piece from penetrating into the ship. This large asteroid, though primarily destroyed, had some smaller pieces slam into and through the Avalon, and damaged the reactor control computer. Without anyway to repair it's damaged reactor control computer, the ship began to use computer resources from other less necessary systems, beginning with the computer control of Chris Pratt’s sleep chamber.