A new MIT study suggests that a Mars mission may lighten its launch load considerably by refueling on the moon. The study assumed that by the time of our next mission to Mars, lunar soil and water ice as well as other minerals would have already been mined and converted to fuel. The MIT team developed a model to assess the best route to Mars with the assumption that resources and fuel-generating infrastructure on the moon are already available. Based on their calculations, they determined that taking a detour to the moon to refuel would reduce the mass of a mission upon launch by 68 percent. The mass-efficient scenario involves launching a crew from Earth with just enough fuel to get into orbit around the Earth. A fuel plant on the moon's surface would then launch tankers of fuel into space, where they would enter gravitational orbit. The tankers would eventually be picked up by the Mars-bound crew, which would then head to a nearby fueling station to gas up before ultimately heading to Mars. MIT Professor of Aeronautics Olivier de Weck says the plan veers away from NASA's "carry along" strategy. “This is completely against the established common wisdom of how to go to Mars, which is a straight shot to Mars, carry everything with you,” says de Weck. “The idea of taking a detour into the lunar system...it’s very unintuitive. But from an optimal network and big-picture view, this could be very affordable in the long term, because you don’t have to ship everything from Earth.”
Past space exploration programs adopted two main strategies in supplying mission crews: the carry-along approach, where all vehicles and resources travel with the crew at all times such as the Apollo moon missions, and the resupply strategy in which resources are replenished regularly, such as by spaceflights to the International Space Station. Such strategies, however, may not be sustainable for explorations beyond Earth’s orbit. The MIT team proposes that missions to Mars and other distant destinations could utilize a supply strategy based on “in-situ resource utilization.” This hinges on the concept that fuel and provisions such as water and oxygen may be produced and gathered along the space exploration route. These materials produced in space would replace those that would otherwise be shipped and carried from Earth.