In space there is no weight and no noise…so the making of the movie took extraordinary measures
“The requirement of realism, paradoxically, compelled Cuarón and his team to pre-visualize the entire film, shot for shot, long in advance of bringing Sandra Bullock and co-star George Clooney onset. This was an animation technique. Each shot was blocked, timed, and the actors "key-framed," creating an "animatic" of the entire script.
Animators had to unlearn years of expectations. Everybody "knows" that objects fly on curved trajectories to the ground based on their weight. But in orbit, weight translates to inertia, there is no ground, and there is only the tiniest hint of gravitational force to change the path.
"It took a lot of education for the animators to fully grasp that the usual laws of cause and effect don’t apply," Cuarón said in a press statement. "In outer space, there is no up; there is no down."
It took more than two years of this "previs" process before the director's first "Action!" call.”