When 'Good Night Oppy', which follows Nasa rovers Opportunity and Spirit before and after they land on Mars, launched at a film festival in September, the documentary had an unexpected effect on audiences: they cried. The film began streaming on Prime Video from 23 November.
"It's funny because I promise you we were not having conversations in the edit room on how we would make people cry," director Ryan White told Reuters.
"It is kind of the shocking, resounding response to this film seems to be people coming up to me sheepishly with their hand over their mouths saying 'I cried about a robot'."
Opportunity (or Oppy) lasted over 14 years until it transmitted its last message on 10 June 2018.
White wanted to make the film after Opportunity's last message "My battery is low and it's getting dark" went viral.
However, it is the film's human characters that evoke an emotional response.
White had assumed scientists and engineers would be very academic and unemotional, posing a filmmaking challenge. "I was totally wrong," said White.
One of the major comparisons made by filmgoers is that the rovers look uncannily like the Pixar Studios animation character "Wall-E".