The best path to Mars could include a pit stop on the moon for gas

MIT scientists have mapped out a route to Mars that would significantly reduce the mass of the mission by using the moon’s resources to refuel en route. It’s a bit of a gamble, because we don’t actually know yet how to use what’s on the moon to make gas.

In a statement announcing the study, MIT explains the advantages of the proposed route:

The team proposes that missions to Mars and other distant destinations may benefit from a supply strategy that hinges on “in-situ resource utilization”—the idea that resources such as fuel, and provisions such as water and oxygen, may be produced and collected along the route of space exploration. Materials produced in space would replace those that would otherwise be transported from Earth.

The plan would lighten the Mars-bound spacecraft by 68%. That would make the mission much cheaper, something researchers Olivier de Weck and Takuto Ishimatsu say is essential: “As budgets are constrained and destinations are far away from home, a well-planned logistics strategy becomes imperative.” Their findings appear in the Journal of Spacecraft and Rockets.

And relying on hypothetical resources is less risky than it appears. De Weck says that, “there’s a pretty high degree of confidence that these resources are available.” And, after all, the whole Mars mission is contingent on scientists figuring out how use Martian resources to sustain life—that’s part of the reason the discovery of Martian water was so edifying. In Ishimatsu’s words, “our ultimate goal is to colonize Mars and to establish a permanent, self-sustainable human presence there…However, equally importantly, I believe that we need to ‘pave a road’ in space so that we can travel between planetary bodies in an affordable way.”

“Paving a road” in space is an idea others have explored as a means of protecting astronauts from prolonged exposure to dangerous radiation. And the idea of stopping on the moon to refuel isn’t new either—it’s come up as an option as scientists puzzle out the best way to bring people to the red planet. But de Weck believes his is the first “definitive paper that shows mathematically why that’s the right answer,” and for now, NASA’s plan has remained to go straight to Mars.