'Interstellar' Cast News, Premiere Date: Matt Damon As Dr. Mann

A surprise addition to the cast of "Interstellar" is Matt Damon. His presence was only noted when the film was seen by reviewers. He had been absent from all promotional material until now.

"Interstellar" is directed by Christopher Nolan who, Business Insider notes, is notorious for releasing very little information about the cast of the movies he directs.

Damon plays the role of Dr. Mann in the movie. His name was not mentioned during the production of the film even though he is a huge star and has starred in many films including the successful Bourne series.

Dr. Mann is one of the many scientists who joined the Lazarus Mission to other planets to see if these other worlds could sustain life. Mann appears to be one of the three astronauts who were able to find a suitable planet. The spaceship Endurance is then sent out to get him and the two other astronauts, bringing with them the data needed to colonize the planets.

Onboard Endurance is Cooper played by Matthew McConaughey, Amelia played by Anne Hathaway and several other crew members. After initially visiting a planet and finding it awash with giant tidal waves, they visit the second planet and find Mann. Soon after finding Mann, they discover that he has lied to them and that the planet is actually filled with ammonia and cannot sustain life.

Mann then proceeds to kill a crew member and later attacks Cooper but is killed when he uses a faulty maneuver to dock with the Endurance. This brings to an end Mann's story line and Damon's appearance in the film.

Business Insider notes that Damon's role is more of an extended cameo appearance and that most people are still not aware of it even though during the filming of "Interstellar" it was briefly reported that Damon would be part of it albeit in "a small secret role."