Simple Reliable Retractable Lunar Lander Solar Array

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 will utilize a very simple pneumatic deployment system to deploy the system and a passive constant torque spring to retract the array.nbsp; 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 the space and lunar surface environments.Recent systems such as NASArsquo;s Roll Out Solar Array (ROSA) and the Composite Beam Roll-Out Array (COBRA) for small satellites have shown the specific power and specific density advantages of a rollable solar array as compared to conventional rigid solar array panels that require mechanical hinges and frames to fold and package the array. These highly efficient coilable arrays have demonstrated specific power values gt; 300W/kg and gt;40 kW/m3.Our array design will take advantage of the current state of the art thin film solar array technology to maximize the benefits of flexible array technology. Specifically, the array will utilize the LISA-T thin film arrays under development by NASA and NeXolve for a variety of applications. nbsp;The LISA-T arrays achieve significant areal density improvements via minimization of the parasitic weight of the array substrate and cover glass. The result is an ultralight weight high efficiency array with exceptional flexibility.