The Martian: Chapter 23 Summary & Analysis

Sol 476. Watney decides he’ll measure how far he is into the storm in terms of “percent power loss”—right now, he’s at 3 percent power loss. The deeper into the storm he goes, the less energy he can budget towards driving. The storm won’t threaten his life support until he’s at 19 percent power loss. Watney sets out to calculate how fast the dust storm is moving, and in what direction. To do this, he’ll set up three solar cells, each 40 km away from the other. By comparing how many watts each cell collects in one day, he can see which way the storm is moving and redirect his path accordingly.

Sol 477. Watney will record the solar cells’ wattage per day by attaching a power meter to each cell and using spare EVA suit cameras to record the power meter. Sol 478. Watney sets up the solar cells and power meter, then eats his “halfway to Shiaparelli” meal. Sol 479. After collecting the solar cells and checking the recordings, Watney determines the storm is north of him. Since it’s moving west, he can avoid the storm by traveling south, then east. Schiaparelli is to the southeast, so Watney won’t have to go too far out of his way.

Sol 480. Watney is on his way out of the storm—his percent power loss each day is decreasing. Even so, he won’t arrive at Schiaparelli on Sol 494 as planned—he’ll have less time than he thought to modify the MAV. Sol 482. Watney spends the “Air Day” reading Johanssen’s ebook of Agatha Christie’s Evil Under the Sun. Sol 484. Watney is finally out of the storm. Schiaparelli is about 1030 km due east, so he’ll arrive around Sol 498—only four sols late.

Sol 487. Watney realizes he is within four sols travel of the Mars exploration rover Opportunity—he could potentially use its radio to contact NASA. This idea appeals to Watney not so much for practical reasons, but because he misses talking to Earth. He’s tired of being alone. But he decides against it. He’ll be at the MAV, which has a radio, in eleven sols—the Opportunity radio is not worth the detour.

Sol 492. Watney starts thinking about a way to leave the bedroom set up all the time once he reaches the MAV (right now, it’s attached to the airlock, so he can’t exit the rover without folding it up). A moment later, he realizes that in order to make plans like this, he has to really believe he’s going to make it to the MAV. Watney decides that once he gets to the MAV, he’ll seal off the “bedroom” and use it to house the oxygenator and atmospheric regulator, then use the trailer as his “bedroom” and workshop.

Sol 497. It’s an Air Day, and Watney will be at the entrance to Schiaparelli tomorrow. He is elated. In the next passage, Weir changes to a third person narration to describe patterns of erosion in the Schiaparelli crater. The “Entrance Ramp” which Watney will drive down, is a slope of compressed sand—but the sand is not evenly compressed. The narrator describes how, as Watney descends the slope in the rover, he hits a patch of soft sand. The rover rolls, and the trailer breaks free and flips. The solar cells go flying. Luckily, the rover’s pressure seal does not breach. Watney is still alive.