I think I spotted only 1 plothole in the entire movie. They never explained how Mat lost communications with NASA, which means that when he explains how there's no way anyone can give him permission to hijack the Ares 4 MAV he's just plain wrong about that.
He could just hook up the Pathfinder (which he's dragging with him across the long trek to the Schiaparelli Crater) and use that to send the message back and forth. And if the Pathfinder had in fact been broken, why is he taking it with him? It's just more dead weight.
He could just hook up the Pathfinder (which he's dragging with him across the long trek to the Schiaparelli Crater) and use that to send the message back and forth. And if the Pathfinder had in fact been broken, why is he taking it with him? It's just more dead weight.