SBIR-STTR Award

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. 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 NASA’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 > 300W/kg and >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. 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. Potential NASA Applications (Limit 1500 characters, approximately 150 words) Initial Lunar Human Lander Lunar Outpost High Power Electric Propulsion Orbit Transfer Vehicles; Orbital Refueling Stations (Retracting partial solar array during inactive periods reduces orbital decay rate) Potential Non-NASA Applications (Limit 1500 characters, approximately 150 words) Commercial and DoD Spacecraft with high power requirements or launch volume constraints DoD Stealthy Satellites

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.