Chapter 2

On Sol 7, Mark Watney assesses his situation. Food for one will last about 300 days (400 if rationed), the Hab is intact, and all EVA suits are functional. Externally, the communications dish is missing, the MDV is wrecked, rovers are buried but intact, and the MAV ascent vehicle is gone. He restores power by cleaning solar panels and verifies the oxygenator and water reclaimer are working.

Watney sets a new mission: reestablish communication with Earth or Hermes. By Sol 10, after multiple EVAs and rover searches, he concedes the comms dish is lost and untraceable. With finite CO2 filters limiting EVAs, he decides to minimize trips and refocus on food production, leveraging his botany skills.

He plans to convert Martian soil into arable earth using human waste to introduce bacteria and nutrients, seeding it with a small supply of Earth soil. He collects and rehydrates sealed crew waste, starts a compost culture, and prepares to “infect” Martian sand, aiming to double viable soil over time. He identifies potatoes as the best calorie crop if they can sprout.

From Sol 15 to Sol 16, Watney hauls soil into the Hab, improvises planters with crew clothing and Hab walls, and confronts water scarcity. He dedicates nearly all reserve water to wet the soil, sacrificing 20 liters for the first five-square-meter plot and enduring the stench of compost. On Thanksgiving, he reflects on his presumed death and resolves to survive for his family.

By Sol 22, two-thirds of the Hab is filled with soil and his first doubling succeeds, but his calorie math is grim: even maximized, potatoes only extend his life by about 90 days, pushing starvation from roughly Sol 400 to Sol 490. He concludes long-term survival still depends on eventual rescue by Ares 4.