Simple Reliable Retractable Lunar Lander Solar Array

Deployable photovoltaic solar arrays are currently the most widely used power source for spacecraft applications. These deployable array systems have been optimized for maximum specific power (W/kg) and maximum specific packaging volume (W/m3) for a given array size and power requirement in a microgravity environment. The structural requirements for these systems have traditionally been derived from minimum stiffness requirements and/or spacecraft guidance, navigation and control (GNC) acceleration rates, not from terrestrial or lunar gravity. The proposed array concept can perform multiple deployment and retraction cycles, and is simple and reliable, and will be relatively low cost compared to more complex fully mechanical systems.nbsp; The proposed system will also be modular and scalable such that elements of the lunar lander array will be directly applicable to building a power infrastructure for lunar surface arrays in the future.nbsp;A new light weight deployable solar power array module is proposed to address the need for a retractable solar array for the initial human lunar lander and future lunar surface applications. The proposed concept leverages recent advancements in thin film solar cell array technology which enables the array to be rolled into a compact cylindrical shape for stowage. The proposed concept uses a very simple pneumatic deployment system to deploy the system and a passive constant torque spring to retract the array. The simplicity and reliability of pneumatic/hydraulic systems have led to their widespread use in aircraft applications. The constant force/torque spring mechanism for retraction requires no power, motors, or controls. The combination of current state of the art flexible thin film solar array technology with a very simple and reliable deployment/retraction system will result in a highly reliable solar array system capable of multiple deployments and retractions in space and lunar surface environments.