MARS science laboratory (MSL) cruise solar array

The solar array is required to supply sufficient power to the space craft as well as charging the lithium ion batteries at all stages of the mission. During the mission the solar array will be shadowed as well as Sun off pointing in all operating conditions. The two most demanding operations for the power system occur just into the final disc at spacecraft integration. Each section has two independently controlled solar array segments for a total of twelve segments. Each segment is comprised of twenty one parallel strings of fifteen cells in series, provided by Emcore Corporation. The array is designed to provide maximum power to fully charge the lithium ion batteries at the final insertion into Mars orbit. This safe mode condition requires that the solar array operate beyond the peak power point while in Earth orbit at the start of the mission. The batteries are located on the MSL rover and handle all power requirements between separation from the cruise array to augmenting the Rover RTG power system on the Mars surface. The solar array falls about 7% short of this goal due to the limited substrate area available. Through out the cruise to Mars the solar array is predicted to meet or exceed the program requirements. As part of the paper the theoretical power calculation compared to performance based measurements of array power will be presented as well as the array design.