SAIL Campaign: Triple Solar Array Demonstration Lights Up LUNA
In November 2025, the LUNA Analog Facility team conducted a series of mission simulations called SAIL (Solar Array Installation in LUNA), which focused on the installation of a solar array under conditions similar to those found at the lunar south pole. In three test runs, different flight control teams at the German Space Operations Center (GSOC) in Oberpfaffenhofen accompanied the missions in real time, while several teams of analogue astronauts (EVA teams) carried out the tasks in the regolith test field of the LUNA facility. The campaign provided an excellent opportunity to investigate both the technical and operational requirements of future power supply structures on the lunar surface.
Each simulation began in the LUNA facility’s ‘airlock’, where the EVA teams conducted mobility tests, checked voice communications with colleagues in the control room and inspected their equipment. After disembarking onto the simulated lunar surface, the crews transported the solar array components on a cart to two designated points of interest, which they explored under the guidance of EUROCOM. The potential for simulating lunar illumination conditions in LUNA was now utilized: The first site was unsuitable due to the shadow of a large boulder and reflected typical lighting challenges at the lunar south pole – The second site in the center of the regolith field, on the other hand, offered stable terrain and sufficient lighting for setting up the solar array.
There, the EVA teams mounted the solar array and connected it to a habitat interface. After activation, a display with voltage and power values confirmed that the system was functioning correctly. The astronauts then collected their tools, removed the simulated moon dust from the equipment and returned to the airlock to complete their mission. The campaign was led by Aileen Rabsahl and Torben Schnathorst.
The triple SAIL demonstration provided valuable insights for the selection of suitable deployment sites, the planning of EVA workflows and the evaluation of the performance of solar technology under realistic analogue conditions. At the same time, the co-operation with various GSOC flight control teams strengthened the readiness for future missions on the lunar surface. Through these joint efforts, the LUNA Analogue Facility continues to contribute to enhancing European capabilities in astronaut training, mission operations and lunar technology development.
Images: DLR/ESA