A mission to Mars via the Moon could launch 68 per cent lighter if technologies to make fuel from lunar resources are in place by the time of the trip, an MIT study suggested.
Aiming to establish the best route to Mars, the team led by aeronautics and astronautics professor Olivier de Weck developed a model enabling them to calculate how the mass of a mission could be reduced, based on alternative routes.
Considering a scenario when fuel can be made from lunar soil and water ice in certain lunar craters, the team concluded the cheapest way to go to Mars would be to launch a crew from the Earth with only as much fuel as required to get to orbit. Once there, the spacecraft would capture a tanker sent from the Moon and head to an orbital refuelling station.
"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," de Weck said. "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."
Getting from the Earth’s surface to orbit is the most energy-demanding phase of any spaceflight. Thus, decreasing the amount of fuel that needs to be carried up would enable major cost savings.
While missions at the International Space Station can rely on receiving supplies regularly from Earth, such an approach would be impossible for a deep space mission. In-situ resource utilisation therefore offers a convenient alternative.
"As budgets are constrained and destinations are far away from home, a well-planned logistics strategy becomes imperative," de Weck said.
The researchers went even further and proposed creating complex resource-producing infrastructure in space that would enable humans to conduct deep space missions repeatedly in a sustainable manner.
"Our ultimate goal is to colonise Mars and to establish a permanent, self-sustainable human presence there," said Takuto Ishimatsu, a PhD researcher and main author of the study. "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."