Getting to the Moon was one of the greatest accomplishments in human history. But now, the Moon may be reduced to a mere pit stop for space travelers headed elsewhere. A Mars mission might be much easier, say researchers at MIT, if we use the Moon as a refueling station.
Slipping the bonds of gravity is the part of a space mission that requires the most energy. Once an object has escaped the pull of one major object, the conventional thinking says, the best plan is to hurtle it at its final destination. But some researchers at MIT disagree. They argue that sending a rocket on a one-way trip to Mars is not the best way to go about the process, particularly if you want to lay the ground work for exploration in the future. The best way to get to Mars is to go back to the Moon.
This two-stage Mission to Mars makes some key assumptions, namely that the soil and water on the Moon can be converted into fuel, and that this can be done in a reasonable amount of time. If you allow those assumptions to stand, then even with the equipment it takes to convert Moon material into fuel, and even with the necessity of making it out of two gravity wells, missions to Mars will be able to jettison 68 percent of their mass.
If our ultimate goal is space exploration, it might not be good to treat every mission as a singular event. The originator of the Moon refueling plan is MIT researcher Takuto Ishimatsu, who has contributed to a host of papers on the various ways to get humanity into space. Making a rocket capable of generating its own fuel, and looking at the bodies in the solar system (and the points between them) as the building blocks of a network instead of single destinations, might be the first step to maintaining a population in space, instead of sending people up briefly and temporarily.
[Source: A Generalized Multi-Commodity Network Flow Model for Space-Exploration Logistics]