NASA SmallSat modular hardware and software standardization

The NASA Explorers Program has initiated a study with the Johns Hopkins Applied Physics Laboratory (JHU/APL) for the purpose of invigorating the Small Explorer (SMEX) program. The goal of this study was to introduce innovative approaches to lower cost and improve the performance of spacecraft and instrument platforms suitable for future small satellite (SmallSat) missions. To achieve this goal, JHU/APL has examined multiple standards from space and non-space industries in an effort to determine how standardization can be used to lower space mission cost without compromising NASA reliability expectations. Through this investigation, a niche was found at the component level (at the slice level for hardware and functional level for software) that is complementary to current DoD standardization efforts and reduces the time required to develop SmallSats. Standardization at this level would enable the development of modular components that can be easily assembled to form avionics boxes or software systems. Developing this capability will reduce nonrecurring engineering through increased re-use and also allow for the localization of mission-to-mission changes that typically drive the costs of SmallSats. The overall H/W standards concept is based on a modular architecture at the slice level that enables modular replacement and modular addition of stacking slices. To achieve this concept, JHU/APL considered stacking systems, various form factors, and modular H/W-S/W interfaces. The overall S/W standards concept is based a process of modular development, testing, warehousing and then drop-in deployment of software applications at the functional level. To achieve this concept, all software interactions whether direct or subtle must be understood and controlled. JHU/APL considered memory protection, time- slice protection, exception protection/self-healing, and bus-like inter-application communication. To gain momentum in the NASA community and to prove these key concepts, a prototyping effort was initiated to explore this concept of standardizing on modular hardware slices and software functions. The results of prototyping work demonstrated that the perceived roadblocks and infrastructure necessary to support a modular, component-level standard could be overcome without deviating far from current practice and currently available technologies. This paper discusses the standardization concepts developed under the NASA SmallSat study including analysis of current standardization efforts, the investigations performed that led to these concepts, and the prototypes developed to prove the concepts. Finally, the paper will discuss future directions for the SmallSat study and the concepts developed.