Everyone is aware of NASA's commitment to a permanent human presence on the Moon, which would act as a kind of 'dress rehearsal' for a manned mission to Mars. However, building a human base on the Moon is a much more complex task than, for instance, building and supporting the International Space Station. Not only is the Moon a thousand times farther away from Earth than the Space Station, building and maintaining a lunar base will require completely new approaches to solving a number of known problems.
The plan is to build the first lunar base as part of the Artemis programme. The first Lunar Module will be built under the Artemis programme and specialists at Sandia National Laboratories have already begun designing a versatile energy system that will link solar arrays, miniaturized nuclear reactors and energy storage devices into a single mini power grid, to which the inhabited and production modules of the base will be connected.
Since one lunar base mission is expected to stay there for one or two months, using solar panels as the main power source is not a viable option. These batteries would be completely useless during the lunar night, which lasts 14 days. Therefore some companies are now working intensively to develop compact nuclear reactors, which can be used with or without solar panels.
However, having the right energy sources is half the battle. The base will be equipped with an intelligent energy system which can transmit energy to the users, guaranteeing an uninterrupted and stable energy supply.
It was envisioned that this first base would be based on two modules, a living quarters and an industrial facility that would process resources extracted from the Moon and synthesize fuel for jet propulsion. For security reasons, the two modules will be separated by a few kilometres, and each module will have its own power supply system, similar to that used on the space station.
The choice of using direct current (DC) or alternating current (AC) has not yet been made; this choice will be made later, given that at some point in time it may be necessary to combine the power systems of the living and production module into a single system.
The Sandia lab is currently developing the Scalable Microgrid facility concept, and is already creating the intelligent software under which the energy system will operate in the future. The system is being built on a modular basis, allowing existing and future components of various types and applications to be connected to it, for which an appropriate software driver will be created.
"There are huge differences between the microgrids deployed on the space station, for example, and what is to be installed on the moon base," says Jack Flicker, an electrical engineer at Sandia Labs. "The biggest difference is the geographical size of the whole thing, which could be a problem if low-voltage direct current is used. The second challenge will be when the power system ramps up with additional consumers, sources and power electronics. The system we are developing will even take into account the physical location of each component, and the intelligent control will ensure the stability and reliability of the whole system.