The movie The Martian wastes no time in getting the lead character stranded on Mars, and my question has to do with the events and details of the opening scene and how they relate to the MAV provided for the Ares IV mission, which Watney uses at the end of the film.
To recap, the scene starts off with Martinez driving out to the MAV site for the Ares III mission to make sure it's not leaning too far for proper use. When the storm hits the force of the wind and particles blowing around cause the MAV's structure to lean, which causes Martinez to note that if the MAV leans further than 12.5 degrees from upright the entire structure will fall over.
Given this, why did NASA send the Ares IV MAV, or for that matter any MAV, so far ahead of missions? Was this one storm meant to be seen as a freak incident? They note that NASA has prepared their equipment and facility to withstand certain storm forces, and that this one is beyond those design parameters, so if it's possible for storms to get this bad on Mars why risk sending the MAVs so far ahead and risk it toppling over due to a storm on the planet long before the arrival of any crew members?
I know they explained that some items were sent ahead to reduce the payload the Hermes has to carry each trip, but the risk of losing vital equipment to storm activity on Mars by sending it that far in advance just baffles me.