431 Concept, Design, and Prototyping of XSAS:   A High Power Extendable Solar Array for CubeSat Applications 

Patrick Senatore*, Andrew Klesh*, Thomas H. Zurbuchen*, Darren McKague* and James Cutler* 

Abstract 

CubeSats have proven themselves as a reliable and cost-effective method to perform experiments in  space, but they are highly constrained by their specifications and size. O ne such constraint is the average  continuous power, about 5 W, which is available to t he typical CubeSat. To improve this constraint, we  have developed the eXtendable Solar Array System (XSAS), a deployable solar array prototype in a  CubeSat package, which can provide an average 23 W of continuous power. The prototype served as a  technology demonstrator for the high risk mechanis ms needed to release, deploy, and control the solar  array. Aside from this drastic power increase, it is in the integration of eac h mechanism, their application  within the small CubeSat form-factor, and the inhe rent passive control benefit of the deployed geometry  that make XSAS a novel design.  In this paper, we discuss the requirements and design process for the  XSAS system and mechanical prototy pe, and provide qualitative and quantit ative results from numerical  simulations and prototype tests. We also discuss fu ture work, including an upcoming NASA zero-gravity  flight campaign, to further improve on XSAS and prepare it for future launch opportunities. 

Introduction   As the availability and frequency of CubeSat launches  increase, it has become evident the CubeSats can  provide opportunities to the scientific community t hat are either unprecedented or normally reserved for  large, complex spacecraft. However, many such missions exceed the typical te chnical performance or  overall constraints of CubeSats, such as their limited power and typical data-rates. In this paper, we present a novel solution to increase the continuous available power on a CubeSat bus from 5 W to 23 W  through the use of a small, deployable solar arra y, which fits within CubeSat volume and mass  constraints.  

Background   Extendable solar arrays from satellites have been extensively discussed in  the literature. By the late  1960’s, work was being done to improve upon existing designs for deployable arrays [1] and several patents were in existence [2]. In the early 1980’s, flexible solar arrays were under study [3] and more  consideration was given to innov ative methods of deployment. Also, inflatable arrays were under  consideration in the 1990’s [4]. Thus by the time CubeSats were conceived in the early part of the century, many types of deployable arrays had been successfully put into practice.   Conforming to a rigid mass and volume standards [5], CubeSats provide a platform for very small (~1 kg, ~10 -3 m3) and often secondary payloads. The CubeSat standa rd, the brainchild of Stanford University and  the California Polytechnic University, is primarily used by universities, although their value is more broadly  recognized by NASA, DOD, and also the traditional aerospace industry . The mass and volume standard  enables launching out of a Poly Picosatellite Orbital D eployer (P-POD) or similar deployment mechanism,  thus CubeSats substantially simplify the launch integr ation: The integrator is  assured that the P-POD  meets certain specifications for launch and the CubeSat has only minimal constraints placed upon it for safety and risk assurance. Since their conception, upwards of 25 CubeSats have been launched with                                                                * University of Michigan, College of Engineering, Ann Arbor, MI 

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

NASA/CP-2010-216272