I've had the great opportunity to be able work on Alfonso Cuaron's "Gravity" during 2011/2012 in Framestore, London.
All the shots above were animated by me and they were completely done by key animation. In certain parts, Sandra Bullock and George Clooney's faces are footage replacements and other parts, everything including their faces are computer generated.
Tough job, most definitely worth it!
You can watch the whole sequence from here.