An Efficient Approach to Subsystem Design: Autonomous GNC - A Case Study

Budgets are shrinking, therefore the space community is focusing on small satellites to satisfy a wide range of applications. New and emerging technologies are helping to make small satellite development less costly. However, matching improvements in the design and development process are also required. In this regard, simulation is playing an increasingly important role. The paper describes the design and development of a typical small satellite's autonomous Guidance, Navigation and Control (GNC) subsystem supported by a graphical simulation tool. The GNC is one of the critical technology elements and could be a significant cost driver on future small satellite programs due to the high costs of the ground segment. The paper will focus on different aspects of GNC design including the on-board software development through concurrent simulation and hardware-in-the-Ioop integration and testing. In introduction, the paper explains the concurrent engineering design approach using a graphical simulation tool. The focus is then shifted onto the Canadian Smart Satellite Mini Platform program. This is followed by a general discussion on autonomous GNC subsystem. The need for establishing a framework for a complete spacecraft simulation architecture is presented followed by a brief description of individual simulation models. In addition, the advantages of using concurrent simulation for on-board software development and GNC design are discussed. In conclusion, the paper describes the advantages of using simulation as a concurrent design tool and the potential benefits gained from autonomous GNC.