Matt asked Andy Weir:

While doing research for this book is there anything you came across that forced you to make a material change in the plot/structure?

Andy Weir Not really. Though there was almost a serious problem with the story because of JPL. After I wrote the whole book and was already selling it, JPL was deciding where to land the Curiosity lander. They had it down to a shortlist of four locations. One of the places they considered was Mawrth Vallis, which Mark drives right through in the book.

Fortunately, JPL chose a different site on the other side of Mars. But if they'd chose Mawrth it would have been awkward. "Why didn't Mark make use of parts from Curiosity? It was like a kilometer from where he was!"

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