The following text contains many book spoilers.
We started the discussion with a short summary of my background and then a student asked about the Martian rover hacking. It is in my opinion, plausible. It depends on several assumptions, such as the rover's driver being able to be modified so easily to log the malformed network data (sent by the probe). It would then be reasonable to send commands to the probe to broadcast the necessary data to construct an executable on the rover. Then assuming that Mark can run it with sufficient privileges or that there is a known vulnerability allowing the executable to gain the privilege, the probe's data could be a patch. Personally, I enjoyed the thought of using ASCII to communicate and myself and my TAs agree, "man ascii". Besides, I carry an ASCII chart in my wallet.
We discussed how there was significant cooperation in solving the problems. The crew worked together. NASA had many teams working on the problems. Internationally, China also provided assistance. The people working on these problems were diverse. And there were continual concerns about the crew's mental state and about Mark's. Similarly, Computer Science students will need to learn to work with others, to work in groups with diverse backgrounds and skill sets, and know that there are many many more people that are wanting to see and willing to support them in having successful lives and taking steps whenever circumstances dictate.
Mark Watney survives in part by having a diverse education and training. Being a fictional character, he has the right skills to survive, but this is based in reality. Astronauts are trained in a diverse set of skills, particularly to maximize the value gained from their time in space. They are not experts, but rather trained well to exercise the guidance of experts on Earth. And similarly, I reinforced to the students that their studies should work to give them a broad foundation beyond Computer Science.
The final topic brought up by the students was about ethics. First, should NASA tell the crew of the Hermes that Mark Watney was alive on Mars, when it was first determined. Or instead, NASA would censor all communication to ensure that they were not informed that they abandoned Mark. What is the trade-off between the truth and mission results? Second, the Chinese scientists had to make a decision, is the life of one astronaut worth their probe? Should they give up their long-prepared mission of great scientific value to instead make a "grocery delivery"? How much is one life worth? Third, when the Rich Purnell plan presented an alternative to rescuing Mark, was NASA obligated to consult the crew in evaluating this option? And related, the crew of the Hermes decided to return to Mars (on the low chance of killing everyone plan) to save Mark Watney, and also extending their mission duration. Also briefly discussed was that governments also have to decide how much a life is worth. It is noted that the science that Mark can perform makes up for the cost of his rescue, which addresses this concern in story.
I think that the 20 or so students appreciated the hour we had together. I hope to some day be able to meet and ultimately teach them in person.