The essay is intended to be a literary analysis of a significant topic; in this case, the focus is the exploration of public interest in Watney’s plight.
How does it(public interest/media attention) contribute to his survival? How/why does the story of this stranded person on mars become more significant than the individual himself? There are real life correlations to be made between media attention on miners being trapped in caves and planes being lost at sea, which should be incorporated into the essay.
One source should be the book itself. The two other sources need to reference real life examples of public interest/media attention and its influence on a plight. Perhaps something like the missing Malaysia plane MH370 or the Chilean Mining Accident of 2010.