Unlike movies where space is "instant," The Martian respects the speed of light. When Watney finally establishes communication, there is a latency of 4 to 24 minutes each way. The film translates this technical hurdle into emotional gold, creating a clunky, silent dialogue of text messages and emojis.
The story’s enduring popularity is also thanks to Mark Watney’s voice. Facing isolation on a barren planet 140 million miles from home, Watney uses humor as a survival mechanism. His journals are filled with snark, self-deprecation, and a relentless "can-do" attitude that prevents the story from becoming too bleak.