Starting from the design outlined in our Mission Concept Summary document, our specialists Martin Lemmens and Michiel Vullings are defining the external surface optical properties needed to maintain the lander's internal equipment within the required operating limits. To analyse the thermal performance of candidate designs, the team is constructing radiative equilibirum models such as as the one shown in the picure below.
This early model includes only the hexagonal body of the lander and a deployable solar array. The lander is offset above a simulated lunar surface.
Following the same approach that was used in NASA's (Lunar) Surveyor missions, the solar array is actuated about one axis. By controlling the roll angle of the lander at the time of touchdown, the rotation axis will point either north or south, and thus it is possible to point the solar array directly at the sun for the complete lunar day.