445 Development of a Solar Array Drive Assembly for CubeSat 

Mike Passaretti* and Ron Hayes* 

Abstract 

Small satellites and in particular CubeSats, have increasingly become more viable as platforms for  payloads typically requiring much larger bus struct ures. As advances in technology make payloads and  instruments for space missions smaller, lighter and more power efficient, a niche market is emerging from the university community to perform rapidly developed, low-cost missions on very small spacecraft - micro, nano, and picosatellites i.   In just the last few years, imaging ii, biologicaliii and new technology demonstration missions have been  either proposed or have flown using variations of th e CubeSat structure as a basis. As these missions  have become more complex, and the CubeSat standard has increased in both size (number of cubes)  and mass, available power has become an issue. Body -mounted solar cells provide a minimal amount of  power; deployable arrays improve on that baseline but are still limited. To truly achieve maximum power,  deployed tracked arrays are necessary. To th is end, Honeybee Robotics S pacecraft Mechanisms  Corporation, along with MMA of Nederland Colorado, has  developed a solar array drive assembly (SADA)  and deployable solar arrays specifically for CubeSat missions. In this paper, we discuss the development  of the SADA.   Introduction 

This SADA has been designed and prototyped specifically  for CubeSat satellites. A CubeSat is a type of  small satellite intended for cost-effective research in lo w Earth orbit space flights.  A CubeSat comprises of  a number of standardized modules or “U's” which measure exactly 10 cm 3, weigh no more than 1  kilogram and are well known to use readily available system components. CubeSats also follow a standard which was pioneered by the California Polyte chnic University and Stanf ord University in 1999. 

Implementation of an articulated solar array drive addr esses the demand for maximal power transfer from  a given solar array assembly. In conjunction with a solar array assembly, the SADA further increases the  effectiveness of “low-cost” CubeSat missions.  A prototype SADA unit has been developed for  demonstration purposes. The protot ype was developed using sound aerospace engineering practices that  pave the way to future flight units. To further enhance the per formance of this system, this SADA will also  be able to support autonomous sun-tracking. The SADA described herein is a simple, self contained,  ultra-thin, low-power, stackable single actuator drive system. This self-contained system is designed to operate on approximately 500 mW of power while articulating the arrays, and less than 1 mW while the actuators and system are inactive . The SADA power system will be supp lied from existing CubeSat power  bus and can accept a range of voltages.     All of this innovative technology is specifically designed to fit in what used to be wasted payload space, a  6.5-mm “slice” of the CubeSat bus. Refer to Figure 1 for the location on the bus where this system is  designed to reside.   

                                                  * Honeybee Robotics Spacecraft Mechan isms Corporation, New York, NY 

Proceedings of the 40th Aerospace Mechanisms Symposium, NASA Kennedy Space Center, May 12-14, 2010  NASA/CP-2010-216272