European Space Agency

Development of a Generic Payload Control System

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Objectives

Integrated Processors are being fitted on new Satellite designs to provide communications flexibility for present and future applications. This flexibility allows configurable antenna beams and variable bandwidth channels to be selected. Advanced techniques are required to command and control these Integrated Processors.

The standard telecommand and telemetry link cannot deal with the speed or the amount of data needed for this control. Thus the Generic Payload Control System is used via an RF link in the ground station to provide a high speed link with a DVB-S modem to send this advanced commanding to configure the Payload, in a time frame consistent with the business need of a Customer’s communications.

The Payload Control System in the Ground Segment is the necessary other half of the Satellite system to be able to fully control the Next Generation Integrated Processors as fitted to Alphasat and for future spacecraft. Conventional channel configuring techniques are not suitable for these Satellites. Thus, the PCS will be designed to control the Payload configurations to enable the full potential of the Payload configurations to be used.

Although these Satellites contain Next Generation Processors, there is a need for the existing Ground infrastructure to be utilised as much as possible. The PCS design will allow the use of existing Ground Station assets as well as incorporating the new features that give the Integrated Processor fitted Satellites the fully configurable options.

As Satellite design complexity increases, so could the operational procedures and so also could the operator interfaces. The PCS design will be developed with support from Satellite Users with operational experience to ensure the design of an operator interface that is intuitive, and usable within a busy Operations Control Centre.

A simple Payload Simulator and a Ground Station Facilities simulator will be included in the design to support the development and provide a self test and training facility.

Challenges

The next Generation Integrated Processors on the Satellite Payload are the fastest and most configurable to date allowing any beam or channel assignment to be used. Thus the Payload Control System has to be able to be equally as fast to use the benefits available. More data than before has to be handled, prioritised and exchanged with the Satellite. Also the Satellite has a higher technical specification, so there is a higher throughput of beam weight information and a calibration interface, which add to the data exchange.

The PCS is supplied as two sets of equipment for equipment redundancy and failure protection. The equipment is being designed as a cross-strapped system which also imposes a complex data handling problem at equipment handover or equipment failure.

The amount of data handling and cross-strapping of equipments are two of the key issues being developed for the first time with the new Satellite Payload.

Benefits

A multi configurable payload controlled by a PCS enables the maximisation of the available spectrum for space communications by enabling any frequency in a band to be used non-contiguously.

Ever higher levels of payload frequency reuse, with high performance can be achieved in combination with the configuration of the multiple beams and generic digital processor based payload technology.

A Satellite system based around Next Generation Processors controlled by the PCS will allow increased operational usage over the full lifetime of a Satellite mission. Satellite operators require an amount of configurability in modern Satellite designs and thus are very reluctant to purchase payloads without the operational benefits of configurable channel bandwidths and steerable and configurable antenna beams.

The ESA supported programme for the PCS with Next Generation Processors is necessary to enable the development of European Flexible Satellite Payloads, thus enabling other European equipment suppliers to develop new technologies to be incorporated into the new Satellite Payloads.

Features

The Payload Control System comprises of two sub-systems, the PCS Manager and the PCS Modem. The purpose of the Manager is to interface to the Ground Station Facilities and any other external interfaces and to construct telecommands originating from these interconnections. The other interfaces which are part of the Integrated Processor Satellite System design connected to the PCS are:- 1) a Payload Calibration Manager, and 2) a Beam Weight Provider. Also a Test Interface connection will also be used during the development and test phases.

The Payload Calibration Manager is a new interface that is part of the overall system design which provides data to maintain the benefits and higher performance of the Integrated Processor fitted Satellite systems. The Beam Weight Provider interface provides the data necessary for the construction of the multiple beam satellite footprints to be created on the Earth, and once configured, to remain in the required positions for the Users on the ground.

Once the PCS has constructed telecommands, they are passed to the PCS Modem application. The Modem application passes telemetry packets which can consist of command acknowledgements or requested data up to the Satellite Payload. The purpose of the PCS Modem sub-system is to implement the High-Speed Link (HSL) communications protocol that will be used to convey Telecommand and Telemetry data between remote applications which connect to the PCS Modem across the Ground infrastructure LAN and the Integrated Processor Sub-System (IPSS) on-board the Spacecraft.


click for larger image

IF =Interface, RFS = RF sensing, GRM = Global Resource Manager, NOC = Networks Operations Centre, SCC = Space craft Control Centre, PMIF = PCS Modem interface

Plan

The Payload Control System is a software project. The hardware consists of one or two PCs/servers and a modem. The development of the project will follow the normal Astrium Company Standards software development. Software modules will be developed and individually tested before being integrated into larger modules and tested. Finally when all modules are integrated, System testing and Validation will be carried out. The PCS will be tested with a test suite, its own IP Simulator and Ground System facilities simulators, and the Satellite Payload. Remote testing will also be carried out with Satellite Ground station equipment across LANs.

Current status

The Generic Payload Control System has just completed FAT. The PCS design with the addition of the Payload Calibration Manager and Beam Weight Provider subsystems has undergone a cost/benefit improvement since CDR to centralise the whole data storage of the PCS, PCM and BWP that make up the Astrium Alphasat Ground Segment. This change considerably reduces the number of FTP connections needed by the Satellite Control Centre, simplifies network operations and improves network configuration and maintenance. The fully flexible cross strapped redundancy is still maintained with this new improvement.

Contacts

Status date

Thursday, February 27, 2014 - 08:59