Portable power supply on the Moon: Introducing the LUNA RTG mock-up
With the NASA Project Artemis well on its way to implement the first human colony on the lunar surface, Lunar exploration and colonisation are no longer a distant dream. At the unique LUNA training facility recently inaugurated at the DLR site in Cologne, astronauts, companies and space-oriented research entities have now the opportunity to train personnel and test technology and scientific equipment, such as rovers, landers or sampling tools, under environmental conditions similar to that on the lunar surface.
Such activities require autonomous, portable and reliable electric power sources. Radioisotope Thermoelectric Generators (RTG) create the perfect conditions for this. RTG have excelled in various space missions, for example on the Voyager probes leaving our solar system, on the Apollo missions exploring Moon and, on the Curiosity, and Perseverance rovers on Mars. They have demonstrated their reliability and longevity. RTG convert the decay heat of radioactive elements into electrical energy through thermoelectric converter modules (TEM), yielding electric power ranging in the hundreds of watt scale. Their small size, high specific power per weight and ease of deployment make this technology highly desirable for the tasks of lunar colonisation.
- On the Moon, an RTG can act as a backup for the central power supply in the lunar base or as a decentralised power source for remote applications.
- With a weight equivalent to around 20 kilograms on Earth, the mock-up can be mounted on small rovers to enable exploration or data gathering in distant regions.
- Moreover, it can act as the cornerstone to power the Extravehicular Activities and Human Surface Mobility program of the Artemis Project, enabling astronaut surface mobility capabilities, a scenario that can easily be tested within the LUNA hall.
- Furthermore, it can power scientific apparatus for continuous data gathering or for communication purposes in regions where availability of solar irradiation is not constant.
- RTG are suitable as a continuous and reliable power source to power robotic units that are planned to kickstart the lunar base construction and subsequently assist humans on their day to day operation during the initial stages of the Artemis Project.
For our astronauts to familiarise with this technology during training at the Cologne LUNA facility, the DLR Institute of Materials Research has developed an electronic RTG mock-up, seen on the right side of Figure 1, which can replicate the behaviour of the RTG. It can provide up to 200 Watts of electric power output and will adapt voltage and current fitting to the user equipment as well as the environment. This includes the mimicked geographical location on the Moon and the angle of incidence of irradiation from the Sun, since that will affect the temperature of the RTG and hence the produced electrical power. The position of the Sun can be input by the user or tracked by optical sensors on the mock-up when making use of the solar simulator within the LUNA facility. A detailed digital twin of a realistic RTG design calculates the temperature distribution in the components of the RTG and its electrical behaviour based on physical models, supporting its reliability in operation, for example triggering a warning in case of non-optimal operation like under too strong solar exposure. During mission operation, the RTG will be wirelessly connected to the control centre, allowing to modify its operating parameters, tracking its status and gathering key data for future mission planning.
The mock-up provides a complete and realistic user experience to prepare customers for their mission to explore the moon and help them take their technology there.
For further information please contact us via luna“at“luna-analog-facility.de
