SAN DIEGO - Prior to Comic-Con, Sandra Bullock didn't realize she should be so worried about her latest movie.

"Not until I started doing press for this a couple days did it start dawning on me how panicked I should be," Bullock told us while out promoting Alfonso Cuaron's forthcoming space thriller at the annual pop-culture fest. "But you can't, because it's not...literally, I say this not being falsely humble, but you don't need the actors in this film that are in this film...the way Alfonso makes a movie, all organisms are smaller parts of a bigger story."

Her answer above was in response to my question about whether she felt pressure being one of only two actors in the film, which follows two astronauts (Bullock and George Clooney) struggling to survive after their shuttle is nearly destroyed by flying space debris. Nevertheless, Bullock claimed that the physical demands of the role were much more in the forefront of her mind during production.

"We didn't have that pressure at all while shooting, because the technology and the unknowns were so vast that we just were trying to get through day to day not knowing if the new technology that we were getting ready to step into to execute whatever scene Alfonso had in his head was gonna work," she said. "So there were physical aspects of it that were much more demanding in terms of, 'Am I gonna get hurt? Are we gonna be able to do it?'"

To check out the rest of the interview, click on the video above.

"Gravity" hits theaters on October 4.