Eurostar 3000 Antenna Tracking System

Objectives

Objective of the project is the development and the qualification of the Eurostar Antenna Tracking System (ATS) functional chain. This includes the architecture design, the system analysis, the control loop design, the FDIR strategy, the software implementation and validation.

Challenges

The following design and development activities were achieved:

  • Antenna Tracking System architecture,
  • Eurostar accommodation of the RFS hardware (mechanical, thermal, electrical),
  • Control loop design and performance demonstration,
  • Equipment management and control loop on-board software development,
  • Antenna Tracking System performances validation on the numerical test bench,
  • Hardware/Software integration and validation,
  • Development and validation of the FDIR mechanisms and the system functions dedicated to the mission and operations management,
  • RF sensing chain validation using EQMs of the RFS units to check electrical interface compatibility.

Benefits

The Antenna Tracking System allows improving the antenna pointing performance down to 0.05°, thus being compatible with multimedia missions and a global capacity of more than 70 Gigabits per second.

The EUROSTAR satellites with Antenna Tracking System enable to offer end-users high speed internet connections to corporate and consumer users comparable to ADSL2 equipped with small diameters (typically 60-80 cm).

Features

The Antenna Tracking System functional chain is based on the following assemblies:

  • Ground beacons (RF transmitters and fixed antennas) located on 4 different beams,
  • Antennas: 4 reflectors and in each feed cluster a RFS (RF Sensing) function implemented,
  • An RF sensing chain in charge of antenna pointing measurement which generates digital data representative of antenna pointing,
  • An ATS control loop software (part of the mission on-board software),
  • Data handling resources (SCU, MPIU, 1553 data bus) to provide command / monitoring capabilities and support for the software application,
  • Antenna Deployment Trimming Mechanisms (ADTM) to control the antenna reflector orientation (one per antenna).


click for larger image

The RF sensing system uses the RF signal transmitted from a ground beacon to measure the angular pointing error of the antennas. These angular pointing errors are then transferred to the on-board data handling subsystem that processes these data and controls the antenna pointing mechanism to minimize the pointing error.

The system beam pointing error is then reduced down to 0.05° including station keeping manoeuvre phase.

This system therefore allows cancelling of:

  • Spacecraft and payload thermo-elastic distortions,
  • Constant biases due to on-ground characterization and integration errors,
  • Attitude errors during the in-orbit correction manoeuvres.

Plan

The project has been carried out within a timeframe of 40 months with the following milestones:

Kick Off December 2006
Baseline Design Review June 2007
Mid-Term Review December 2008
Test Readiness Review May 2009
Test Review Board March 2010
Final Review March 2010

Current status

Final Review held with ESA on the 30th of March 2010.

Contacts

Status date

Thursday, October 14, 2010 - 15:52