Design approach and challenges for the iridium next constellation command and control system

Abstract

Scheduled to be fully operational in 2018, the Iridium NEXT constellation will continue to be the largest commercial satellite constellation in operation. In total, it will consist of 66 cross-linked satellites and 9 in-orbit spares operating in a Low-Earth Orbit (LEO), providing communication services to a variety of customers and industries. Iridium and L3 Technologies have worked together to design the Iridium NEXT Satellite Control System, specifically the Command and Control (C2) subsystem-based on L3’s InControl product architecture. This paper will focus on the overall design of the C2 subsystem, from its inception to its actual deployment and integration into a larger Ground Segment at Iridium’s facilities. Various techniques and optimizations employed to overcome the technical challenges are discussed. In terms of infrastructure, going with a virtualized approach was a clear winner. This paper will discuss how operational services were strategically distributed across virtual machines and storage resources to support fault-tolerance and redundancy as needed for 24/7 operation support and high-availability systems. Configuration management for a single satellite is easy compared to managing the databases and configuration changes required for an entire fleet. The challenge of managing a large fleet resulted in the development of various scripts and utilities, as well as a more formal configuration management approach. Simulating this large fleet during project development and test phases proved very challenging as well, and in the end exposed many performance and scalability issues that had to be addressed. Finally, the biggest challenge and most important aspect was automation at various levels. Single spacecraft procedure automation was already readily supported by the C2 software, however for this constellation, automation and resource orchestration was required at a higher level, for the growing fleet and up to the full constellation. The Iridium team was able to use the API layer of the C2 system to automate all nominal daily operations activities and integrate this into a full mission planning, scheduling and control solution.