Rich Purnell

Lore & Background

Rich Purnell is a NASA astrodynamicist. He devises a "slingshot" trajectory around Earth for a gravity assist that could get Hermes back to Mars on a much-extended mission to save Watney, using the Chinese rocket booster to send a simpler resupply probe to Hermes as it passes Earth. NASA Administrator Teddy Sanders vetoes the "Rich Purnell Maneuver," as it would entail risking the other crewmembers. However, Mitch Henderson, the Ares 3 flight director, secretly emails the details to Hermes. All five of Watney's crewmates approve the plan. Once they begin the maneuver, having disabled the remote overrides, NASA has no choice but to support them. The resupply ship docks with Hermes successfully.

Reader's Guide

Rich Purnell is a supporting character whose arc demonstrates the power of expertise and persistence. He is an astrodynamicist at JPL, initially portrayed as a background figure overshadowed by more vocal engineers. His key skill is his unparalleled ability to calculate complex orbital trajectories, which he uses to devise the risky but necessary 'Rich Purnell Maneuver.' This plan involves using Earth's gravity to accelerate the Hermes back to Mars, a concept that faces fierce opposition from NASA leadership due to its danger to the crew.

Purnell's defining moment comes when he bypasses his superiors and directly presents his calculations to Vincent Kapoor, sparking a chain of events that leads to the rescue. His arc highlights the theme that heroism can come from the most unlikely, introverted individuals—people who would rather talk to a spreadsheet than a crowd, but who will fight like hell for what the numbers say is right.