The Rich Purnell Maneuver

Lore & Background

The Rich Purnell Maneuver is named after its creator, Rich Purnell, a brilliant but socially awkward astrodynamicist at NASA's Jet Propulsion Laboratory. In the story, Purnell calculates that the Hermes spacecraft, which is returning to Earth after aborting the Mars mission, can use Earth's gravity to perform a slingshot maneuver. This would send it back toward Mars, intercepting Watney's position at the Schiaparelli crater. The maneuver requires precise timing and an extremely tight fuel budget, leaving no margin for error. NASA initially rejects it as too dangerous, but the Hermes crew, led by Commander Lewis, learns of the plan and decides to proceed against orders, forcing NASA's hand. The maneuver succeeds, making Watney the first human to be rescued from another planet.

In Their Own Story

The Hermes glides silently through the black void, its crew huddled around a flickering screen. Commander Lewis reads the message from Earth: 'Rich Purnell has a plan.' She looks at her team—Johanssen, Beck, Martinez, Vogel—their faces a mix of hope and fear. 'We're going back,' she says. The room buzzes with tension as they calculate the burn: a slingshot around Earth, then a long, lonely arc to Mars. No one speaks of the odds, but everyone knows: this is their only chance.

Reader's Guide

The Rich Purnell Maneuver is a key plot device in The Martian, representing the intersection of human desperation and scientific precision. It is devised by Rich Purnell, a NASA astrodynamicist, who calculates that the Hermes spacecraft can use Earth's gravity to slingshot back to Mars, intercepting Mark Watney's location. The maneuver is highly risky, requiring the Hermes crew to endure an extended mission and a dangerous supply resupply from Earth. NASA initially rejects the plan due to its dangers, but the Hermes crew, upon learning of it, decides to proceed against orders. This mutiny forces NASA to support the maneuver, leading to a tense sequence of events. The maneuver succeeds, allowing Watney to be rescued from the Martian surface. It highlights themes of teamwork, ingenuity, and the willingness to take extreme risks for a single life. The maneuver's success depends on precise calculations and the crew's ability to execute a complex orbital trajectory. It is a fan-favorite moment, celebrated for its blend of hard science and human drama.

Did You Know?

• The maneuver is named after the character Rich Purnell, who is based on real-life NASA astrodynamicists like those who plot gravity-assist trajectories for planetary missions.
• In the novel, the maneuver is described in excruciating detail, including the specific orbital mechanics—delta-v, transfer windows, and the exact geometry of the Earth flyby.
• The plan requires the Hermes to perform a gravity assist around Earth, a technique used in real space missions like Voyager and Cassini to steal momentum from a planet's orbit.
• The maneuver's success hinges on a supply resupply mission from Earth, depicted as a tense, high-stakes operation where a single misfire means the crew starves or the trajectory fails.