In the last few years, there have been discussions of building a lunar base to use as a refuelling station for the Mars missions, and now a new study from the Massachusetts Institute of Technology has worked out the best way to achieve that. The research, which is based on the doctoral work of Takuto Ishimatsu, will be published in the Journal of Spacecraft and Rockets.
The cost of missions depends strongly on the weight of the payload to be put in orbit. The increase in the use of tiny CubeSats and the compact Indian Mars Orbiter Mission highlight a trend in space exploration that focuses on miniaturization, with the aim of saving money.
Historically, only two load-carrying strategies have been adopted in crewed space exploration. You either bring everything with you (like in the Apollo missions) or you need to take into account regular re-supply missions (used for the space stations). A proposed third way is to carry the essentials and use the material found in-situ to construct and produce other necessities.
The team behind the research believes that the third option is the most viable. Long distance missions beyond the Earth’s orbit could not be easily re-supplied, and carrying everything is a very expensive approach for space agencies battling with shrinking budgets. NASA states that it costs $10,000 (£6,500) to put 450 grams (1 pound) of payload into space.
Water ice found on the Moon and Mars could be used to produce rocket fuel, as well as providing water and oxygen for the astronauts. The study suggests that this could reduce the launch mass of a potential Mars mission by 68%.
The group proposes a scenario in which we have infrastructure on the Moon focused on the mining of lunar ice to produce fuel. The crew will launch from Earth with enough fuel to reach the orbit of the Moon, then, while on the surface of our natural satellite, produce fuel, put it into tankers and launch it into space, where it would enter gravitational orbit. The crew would eventually pick it up on its way to Mars.
According to the team, this "pit-stop" Moon proposal is the most cost-effective scenario, even including the necessary launches to bring infrastructure and possibly crew to the lunar surface, who would be responsible for generating the fuel and sending it up.
