After an accident in space, astronaut Troy Holloway is trapped in a space capsule that heads to the Sun with only 90 minutes of oxygen left. Caught in a trap on a space capsule that goes to the Sun, he quickly realizes the true horror of his situation. The only way to help him is with Commander Roberts, who speaks to him through a poor radio transmission, telling him he will lead a rescue team.
With a rapid exhaustion of oxygen, commander Roberts is determined to rescue Holloway before time runs out. After he recently lost his son and now faces his immediate end, Holloway feels less enthusiastic about the idea of survival. As things get worse, Troy wonders if he really wants to be saved, as the pair begins to influence each other in unexpected ways.