Earlier this month, we brought you a report about Warner Bros. trying to get Sandra Bullock to take the lead role in Gravity, written by Alfonso Cuarón and his son, Jonas Cuarón. The film has had Robert Downey Jr. slated to star as the leader of a team posted at a space station, where he and a female colleague (possibly Bullock) are traveling outside the space station, the other team members are decimated by debris from an exploded satellite.

Now, Deadline reports that Bullock is “locked in” for the role but, Robert Downey Jr. is reportedly leaving the project due to scheduling conflicts. The screenplay focuses on Bullock’s character, and Downey Jr.’s character would have been a smaller supporting role, as the only other surviving astronaut.

Warner Bros. has denied that RDJ is leaving the film, stating that the scheduling issues are expected to be resolved. The actor was originally set to shoot Gravity before shooting on Guy Ritchie‘s upcoming Sherlock Holmes 2 began. Then it was said that he would take a break in the middle of filming the as yet Untitled Sherlock Holmes Sequel to film his role in Gravity. Because the Sherlock sequel is currently in production, neither of those plans seem to have worked out.

Stick with us for the latest on any developments.

Gravity is slated to hit theaters in 2011.