In this chapter, Mark Watney attempts to take hydrazine and make it into water, and he is successful, although he doesn't make very much of it. He only succeeds in making about 50 liters of water. A typical 8 minute shower uses about 62 liters of water, and some power showers use up to 136 liters of water, whilst a typical bathtub uses roughly 80 liters of water. So, 50 liters is not very much at all. He also succeeds in making the HAB a bomb by filling it with pure hydrogen, which can explode with just a small spark. while burning hydrazine and converting it to hydrogen and O2, he thought he was using all of the hydrogen, but then he realized that not all of the hydrogen was being burnt, which meant that there was unburnt hydrogen floating around in the HAB, and that's not a good thing at all. The unburnt hydrogen can ignite and blow up at any time, which is not good for human being.
Chapter 5
In this chapter, Watney cowers in a rover while he waits for the HAB to clear out, and once he decides it's safe to go back in, he returns. He decides to make more oxygen, so he continues to burn hydrogen, but ends up making a bomb that explodes, causing him to nearly loose his hearing and pass out. He survives the explosion and he makes sure everything is running properly, then he gets back to burning hydrogen to make oxygen.
Chapter 6
In this chapter, NASA has a memorial for Mark Watney, who they presume is dead, but then Mindy Parks, an employee from SatCon, discovers that Mark Watney is alive. Following that shocking discovery, NASA's highest executives in charge of the Mars program scramble to confirm that Watney is alive, and how to communicate with him to make sure he is okay.
