Operations Planning for the Galileo Constellation

Abstract

The Spacecraft Constellation Planning Facility (SCPF) is responsible for the operations planning of all thirty-plus satellites, five ground stations and the control centres. It generates a “Short-Term Plan” of contacts, tasks and activities, based on the requirements of the navigation service and the satellites’ flight control. Its key functions are: automated routine planning, special operations planning, ground-station contact planning, operations plan production and validation, and planning rules configuration. A typical week for Galileo consists of 300+ satellite contacts and perhaps 1,500 tasks with 10,000 separately schedulable procedures and on-board commands to be executed. The SCPF must automatically produce a viable week’s plan in just 10 minutes. This is possible because design enables all routine operations to be planned automatically. Additionally, special operations such as spacecraft manoeuvres and other critical maintenance procedures can be integrated into the routine operations. This integration is planned to minimise disruption to the currently loaded spacecraft and control centre automation timelines, significantly reducing operator workload. Requests for special operations are submitted and managed using a generic service, allowing requests to arrive from several other system functions such as flight dynamics, satellite maintenance and security. The complete operations plan is then supplied as a generic service for execution by on-board and control centre automation functions. The state of the current operations plan is then maintained by the receipt of execution feedback from the automation functions. The planning application is designed to be highly configurable to address the evolving mission operations concept. A separate database editing application allows satellites and stations to be added, new satellite resources and new flight rules to be defined. This paper discusses the key requirements of the constellation’s operations planning and how the design of the tool satisfies them. Special focus is given to the planning of the contacts needed to support operations versus the ground station utilisation. The planning algorithm has been developed after extensive programme of prototyping and has demonstrated excellent performance over a wide range of