Martian movie time software#
This proved far too difficult to do with pen and paper, but Weir’s background as an application developer enabled him create software that would generate and track the orbits as needed. Weir needed to ensure that the radio signal time delay between Earth and Mars, and between Earth and Hermes, is "accurate." And as the planets’ positions shift through the hundreds of days across which the story takes place, the radio delays are exactly what they should be. This required actually working out the specifics of the book’s Mars mission in great detail, including constructing an ephemeris of the solar system’s bodies and simulating several years’ worth of orbits to find exactly the right time period. Quoting the relevant section:įor example, in order for there to be potatoes available for Watney to grow, Weir had to time the Mars mission such that it took place over a Thanksgiving holiday. Once he had that figured out, the entire timing of the story flowed backward from that. He had to find a year where the transfer orbits to Mars worked out such that the crew could spend Thanksgiving on the surface, thus necessitating the potatoes. When I interviewed Andy for my feature on The Martian last year, he said that he very deliberately didn't reveal the year in which the story takes place, preferring to leave it as an Easter egg for readers to figure out.