According to Ong, intertextuality is the idea that text often shares similar basic storylines. Intertextuality can be seen in Andy Weir’s The Martian with an overused “stranded person” storyline. However, this does not mean that his story is exactly the same as every other. He incorporates his own knowledge and passion about space, physics, chemistry, biology, etc. in order to create an engaging and realistic story that nobody else could have written (for example, the part when Mark Watney uses the bacteria in his feces to encourage potato growth in a supposedly uninhabitable land). With this I want to acknowledge that although intertextuality is inevitable, it does not mean every story is completely unoriginal.
The Martian is also original in its writing style with Watney’s journal entries. Watney’s one-sided diary-like entries are a form of secondary orality because there is no conversation happening. Watney creates these entries with the assumption that after he dies, somebody might find them and listen to his story, but by the time this somebody receives the message, Watney will supposedly be dead. Although the journal is not a written journal and rather an oral journal, it is still considered secondary orality because the diary is recorded, and therefore definitive and cannot be changed in the future. This is why he explains very fully the details of every day and the reasoning behind his actions so there are no questions left for him.
On the other hand, when he contacts Earth with Pathfinder and communicates through written messages, it is primary orality because there Watney is fully aware and on the other side, and there is an active and ongoing conversation between him and his friends on Earth. He is able to, and does, clarify anything for the people on the other side about how he was able to survive for so long.