Private Public Cooperation for Hosted Payload Operations: the Alphasat Concept

Alphasat, the first satellite based on the new Alphabus platform. was launched in July 2013. Built by a consortium led by Airbus Defense and Space, owned and operated by Inmarsat for a GEO-mobile mission, it carries on board four hosted payloads. These Technology Demonstration Payloads (TDPs) have been procured through ESA, and ESA is also responsible for their operations. Given the very different nature of the commercial primary mission of the satellite, and the scientific, experimental mission of its hosted payloads (the TDPs), an ad-hoc concept of operation has been devised. This concept needed primarily to consider that the commercial operator of the satellite had to include the new satellite into its fleet of multi-families (from different makers) satellites, controlled via a unified monitoring and control system (UMCS). The operations concept for the TDPs has been therefore designed to interface with the existing ground segment systems minimising (or avoiding wherever possible) the need for modifications. The resulting concept aims at making the activities of the TDPs de-coupled from, and transparent to the commercial operations execution. This has been achieved by establishing an upstream coordination and interfacing entity, capable of providing the required exchanges of data for in-flight operations, while minimizing the impact in the Inmarsat satellite control centre, both for the operations planning and the TDPs monitoring functions. . On the monitoring side, a relatively straightforward solution is identified; with the implementation of a “black-box” approach to TDPs operations, based on a non-interference basic rule. On the controlling side, the same approach is complicated by the need to provide consistent and consolidated operational requests to the commercial operator in line with the operations execution products (TC sequences, procedures, etc) validated in cooperation with the satellite manufacturer. In its first year of operations, Alphasat and its hosted payloads have been providing to Inmarsat and ESA, a still growing experience in designing and implementing the operations for hosted payloads, in a cooperative effort shared by all the (several) other actors involved.