I found this awesome interview of Andy Weir with Adam Savage. You will recognize Savage from the show "Mythbusters".

During the interview Andy Weir gives great details about his life and the development of "The Martian".

The interview is 55 minutes but is well worth it.

https://www.youtube.com/watch?v=5SemyzKgaUU

fantastic! Andy's an inspiration, and some fascinating insights into practical author stuff in there, and plenty more, just as you said Taylor, well worth it.

Weirs' parents had interesting careers, Dad, a physicist, Mum, an electrical engineer. Weir grew up a space program geek. Its interesting that Weir had no contact with any space agency's or astronauts even through the print publication of The Martian. Weir credits time spent watching hour after hour of documentary film of anything space flight related for giving him the foundational exactness of the science involved and the personalities of astronauts that he incorporated into his story. For Weir, calculating launch schedules was just sort of a hobby.