The Hermes Program

Lore & Background

The Hermes spacecraft was a marvel of engineering, built over years of international collaboration. Its ion propulsion system, powered by a nuclear reactor, allowed for efficient travel, drastically reducing travel time between Earth and Mars compared to conventional chemical rockets. The ship was designed for modularity, with habitation modules, laboratories, and storage sections that could be reconfigured for different mission needs. Its life support systems were closed-loop, recycling air and water to sustain a crew of six for months in deep space. Hermes was not just a vehicle but a symbol of humanity's collective ambition. It served as the home and workplace for the Ares crews during their months-long journeys, and its reliability was tested to the limit during the Ares III mission. When Mark Watney was stranded on Mars, Hermes became the linchpin of the rescue plan, requiring a daring slingshot maneuver around Earth to return to Mars faster. The ship's design prioritized crew safety and redundancy, with backup systems for critical functions. Its ion drives, while efficient, required careful management of propellant and power, making every mission a delicate balance of resources. Hermes used a rotating section to generate artificial gravity, mitigating the health effects of prolonged weightlessness.

In Their Own Story

The alarm blared through Hermes' corridors—a sharp, insistent tone that cut through the low hum of the ion drives like a knife. Commander Lewis was already at the console, her fingers flying across the touchscreen, eyes locked on the trajectory plot. 'We're burning too much propellant,' she said, her voice flat but carrying an edge that made the crew snap to attention. 'If we don't correct, we'll miss the Earth flyby window—and Watney stays dead.' The crew moved with practiced urgency, hands dancing over controls as the ship groaned, its frame flexing under the unrelenting stress of the maneuver. Through the aft cameras, Mars shrank to a rust-colored marble, then a speck. Hermes held, as it always had, carrying them home—and back to Mark.

Reader's Guide

The Hermes Program was NASA's answer to the impossible: a reusable spacecraft that could make multiple trips between Earth and Mars without being discarded after each use. Powered by a nuclear reactor feeding xenon ion drives, Hermes offered continuous, gentle thrust—accelerating day after day to cut transit times from months to weeks. The ship was built in orbit, a jigsaw puzzle of modules launched by the U.S., Russia, Europe, and Japan over several years, then mated together by spacewalking crews. Hermes served as the transport for the Ares missions, each crew spending months aboard during the journey. Its design included living quarters with private bunks, a galley with a fold-down table, a gym with elastic resistance bands, and a laboratory for experiments—all optimized for long-duration habitation. The ship's rotating section, a ring of hab modules spun to create artificial gravity, helped prevent bone loss and muscle atrophy, giving the crew a taste of weight they'd miss on the Martian surface. Every system—from the water recycler that turned sweat into drinking water to the backup oxygen generators—was built with redundancy, because in deep space, there's no hardware store.

Did You Know?

• The Hermes was assembled in Earth orbit over several years, using modules launched by multiple space agencies.
• Its ion propulsion system could run continuously for months, providing gentle but constant acceleration.
• The ship's rotating section generated artificial gravity, helping to prevent bone and muscle loss in the crew.
• During the Ares III rescue, Hermes performed a slingshot maneuver around Earth to return to Mars faster.