As Chapter 13 begins, Watney communicates with NASA via the rover. NASA has begun team-reviewing Watney’s plans for the Hab, including his cultivation of potatoes, to make sure all his actions check out and will make possible his survival. At first, Watney is frustrated at NASA’s butting in, since he was able to survive for months on Mars with no input whatsoever. But Kapoor, over rover-mail, convinces Watney that he should listen to NASA—that they have his best interests at heart. Watney also communicates with his parents and Commander Lewis, who apologizes to Watney for leaving him; Watney rejects her apology, saying that Lewis did the right thing, and that he’ll support her as a commander unwaveringly (should there be a congressional inquiry into her actions). The NASA plan for rescuing Watney, as it stands now, is to drop supplies for him at some point in the next couple years, and to arrange for his safe conveyance to the Ares 4 location. The Ares 4 crew will then shed weight, when they land on Mars, and pick up Watney for an eventual return to Earth.
As Chapter 13 continues, however, Weir interlaces italicized sections describing the physical material comprising the Hab’s airlocks. While Watney is going about his normal business, entering and leaving the Hab mostly through airlock 1, the super-high-strength materials of which the Hab is manufactured begin to experience small tears. At the end of the chapter, when Watney reenters the Hab after a short walk to the rover, the airlock blows open, hits Watney in the face, and causes the Hab to depressurize instantly and “collapse” on itself. Watney can’t believe his bad luck. Watney finds himself sealed in the airlock many meters from the Hab, with a broken faceplate, looking on at his deflated dwelling. He’s initially frustrated and upset, but realizes that only a rational outlook will help him troubleshoot the problem. His suit can replace some of the air pressure that the airlock is losing, but Watney realizes he’ll need a new suit, and a sprint to the rover, to reach a “safe pressure” zone long enough to allow him to repair the Hab. Craftily, Watney cuts off part of his own spacesuit to patch over the crack in his faceplate, then seals the faceplate and the arm of his suit (from which the patch was taken) with emergency resin, included with the suit. He rolls the airlock end-over-end to reach the Hab, then picks up a new space helmet and skips carefully over to the rover, just making it before his suit’s oxygen reserves give out. Taking stock of events in the rover, he realizes he’ll have to work hard to get the Hab back to liveable shape. But at least, as he notes, he’s still alive, and can work with the materials he has to salvage the Hab and continue in his planned rendezvous mission with Ares 4, at Schiaparelli.
Watney sleeps overnight in the rover, then tops up his spacesuit with air (now featuring the new helmet, from the brief trip to the Hab). He returns to the Hab and, with more available oxygen to facilitate searching, is able to snag a new, full spacesuit, to replace the one-armed, repaired one he’s currently wearing; he can change suits back in the rover. He also uses rocks to spell an “A-OK” message to Houston, which, he fears, has seen images of the airlock blown off, and probably worries about Watney’s condition. Now that Watney has a stable spacesuit and helmet, and a temporary “base” in the rover, he can survey the damage fully. He’s resigned over the airlock’s small tear, but the airlock itself has blown clear off the Hab. Watney will need to use enormous pieces of extra canvas to patch over the former airlock hole in the base, and will need to use another airlock for re-entry from now own. Watney also realizes, to his chagrin, that all the potato plants still in the “ground” in the Hab have died, from the rapid depressurization of the airlock explosion. Watney has stored some mature potatoes outside in the freezing cold of Mars, for safekeeping; thus he has some food, but no longer the ability to grow future potatoes. He calculates that he’s lost about a year’s worth of food, which will make survival difficult for the necessary three-odd years until the arrival of Ares 4 at Schiaparelli. He doesn’t yet know where his additional food will come from.
Watney is able to patch the hole in the Hab and repressurize it, and he has two airlocks left to use for exit and entry. The rover is intact, and his Pathfinder link with NASA also works. He’s able, after several days, to get all Hab systems back in place, including the oxygenator and water reclaimer, and he begins communicating again with Kapoor and others at NASA, who are thrilled that Watney is alive. Everyone realizes that a new probe, carrying emergency food supplies, will have to be built and launched to Mars in about a month and a half, otherwise Watney will run out of food before Ares 4 lands on the Red Planet. Everyone at NASA and its affiliated programs begins working round-the-clock to launch just such a supply probe.
NASA calls this probe Iris, and its payload consists entirely of “protein cubes,” for Watney’s nutrition, and a radio to supplement the Pathfinder currently used for comms. NASA, JPL, and enormous staffs of employees on overtime do everything they can to manufacture the probe and plan the launch in around 40 days. Because JPL runs behind on the design of important launch systems, Sanders asks, at an all-hands meeting, that the launch forego certain inspections, which will raise the probability of launch failure to 2.5%. This is an “unacceptable” risk in standard NASA parlance, but necessary in the current instance, because there is no backup plan to feed Watney in time. Incredibly, the Iris probe is assembled at attached to a rocket already waiting (and scheduled for another mission) at Cape Canaveral. The launch occurs before the entire world, watching on TV, and for the first twenty-odd seconds, all appears to be going smoothly. But, as the narrator reveals, a small amount of fuel “sloshes” around, imbalanced, within the rocket, altering its trajectory and creating a severe counterforce, causing the rocket to deviate from its orbit and break apart into small pieces. The Iris probe has failed to launch, leaving Watney with no long-term prospect of food.
The theme of patience finds, in this section, one of its clearest manifestations, as Watney tries to sort through the aftermath of the airlock explosion. Watney has worked painstakingly for months to grow potatoes in the Hab, and is emotionally devastated to see the Hab deflated, with his botanical work inside destroyed. But Watney’s patience and foresight has also paid off, as he was prudent enough to store some potatoes out in the Martian environment, “flash-freezing” them. This cache of food allows Watney at least some time to continue in his repairs, while he and NASA work out a replenishment mission that can keep him alive longer. Watney understands that the explosion of airlock 1 has nothing to do with any one action—that it’s the result of material used far past its design period. Everything Watney does on Mars is improvised, and if one solution doesn’t work, he must keep heart and find another one, no matter how dire the circumstances appear to be.
The Hab is one of the novel’s more prominent symbols: a beacon of hope and life for Watney, on a planet that seems otherwise hell-bent on destroying him. NASA engineers designed the Hab to support a crew of six for only a number of months, but Watney is using it to keep himself alive for years. The Hab is thus analogous to Robinson Crusoe’s island: the space that becomes, for the length of the novel, the protagonist’s entire world. When bad things happen to the Hab (when the airlock bursts, or when Watney ignites a small explosion while making water), Watney’s life on Mars is threatened terribly. And Watney admits that, when he’s out of sight of the Hab, he gets nervous, feeling that he’s left behind the part of the Martian surface he knows best. Although Watney doesn’t tend to approach problems in allegorical terms, it makes sense, at this stage of the novel, to consider its allegorical as well as its realist, scientific dimensions. Watney is in an extreme situation on Mars, far beyond what life on Earth would demand. No one has stayed on Mars as long as he has, and Watney admits to himself that he’s proud to have reached innumerable Martian milestones (longest EVA, longest rover ride, etc.). But Watney’s struggle on Mars isn’t wholly different from humans’ struggles on Earth, with problems of nearly unimaginable size. The Earth, too, presents challenges for survival, as Robinson Crusoe’s time on his little island attests. History moves forward, and humankind’s technological know-how increases enormously. But humans tend to push themselves to their physical, philosophical, and spiritual limits. And in this sense, Watney’s journey into space, his marooning on Mars, represents a further step in the very human urge to explore as far, or perhaps farther, than was previously thought possible.