ESA’s GSTB Programme

1. ESA’s GSTB Programme • GSTB-V1 is a ground system to test Galileo’s key algorithms using GPS data • GSTB-V2 consists of a pair of satellites: • GSTB-V2/A (SSTL) – now known as Giove-A launched in December 2005 • GSTB-V2/B (Galileo Industries) backup satellite in case of launch failures etc. Due to be launched in April 2006. • GSTB-V2 contract worth £20M awarded to SSTL in July 2003

2. Giove-A Platform • Platform • Dimensions: 1.3m x 1.3m x 1.4m (stowed) • Wet mass: 660kg • Power generation: Sun tracking arrays • Sensors: EHS, ASS, Gyro • Actuators: Wheels, Magnetorquers, Thrusters • Pointing: ±0.55° pitch/roll required (3), ±0.1° achieved; ±2.1° yaw required, ±1.0° achieved • Orbit determination: NORAD, Laser ranging, GPS, reverse GNSS • Propulsion: 90 ms-1v butane system • TT&C: S-Band • Avionics: SSTL Enhanced Microsat

3. Giove-A Navigation Payload • Custom payload designed by SSTL • Payload items supplied by ESA through contracts with third parties: • Alcatel Espacio (Spain) – Clock Monitoring & Control Unit • Norspace (Norway) – Frequency Generation & Upconvertor Unit • Alenia (Italy) – Wide-band Radiating Antenna System • Laben (Italy) – Navigation Signal Generation Unit • Temex (Switzerland) – Rubidium Atomic Frequency Standard (stable to 10 ns per day)

4. Giove-A Environmental Payloads • MERLIN – QinetiQ • Cosmic-Ray LET Spectra • Proton Flux • Total Ionising Dose • Electrons/ Deep Charging Currents • CEDEX – UniS/SSTL • Cosmic-Ray LET Spectra • Proton Flux • Dose-Rate Induced Photocurrents CEDEX Space Weather Monitor

5. Giove-A Experimental Payloads • GPS Receiver – SSTL • Laser Retro-Reflector SSTL Miniature Space GPS Receiver Laser Retro-Reflector Array CEDEX Radiation Monitor MERLIN Radiation Monitor GPS Receiver Antenna

6. Giove-A Payload Architecture • Payloads: Navigation, Environmental and Experimental

7. Giove-A AIT Antenna Payload Bay Avionics Bay Propulsion Bay Giove-A Flight Model 1st Integration at the Surrey Space Centre, University of Surrey, Summer 2005

8. Launch! • Launch Day: 28th December 2005 05:19 UTC • Soyuz launch vehicle from Baikonur • Fregat upper stage to inject Giove-A into the correct Galileo orbit

9. LEOP • Communications were established with the SSTL ground-station at the University of Surrey immediately upon separation. • Telemetry received at Surrey, Bangalore, India and Kuala Lumpur, Malaysia, in conjunction with the 12m satellite tracking antenna at RAL, showed all systems were nominal. • The solar arrays deployed perfectly, and initial operations were completed ahead of schedule.

10. First Navigation Signals • Europe’s first Galileo navigation signals were transmitted by Giove-A at 17:25 UTC on 12th January 2006. • The signals were commanded on from Surrey and the Galileo signals were received by the 25m antenna at the CCLRC Chilbolton Observatory, Andover, UK and the ESA Earth-Station in Redu, Belgium • The Galileo E5 and L1 channel signals were successfully decoded by a Galileo Navigation Receiver at Surrey...

11. Conclusions • In July 2003 SSTL embarked on its most complex project ever – the design and construction of a totally new 600kg+ satellite for use in Medium Earth Orbit. • Surrey rose to the challenge and, just 24 months later, delivered the Giove-A satellite to ESA for environmental testing. • The Soyuz launch from Baikonur was successful, and platform commissioning was completed ahead of schedule. • On 12th January 2006, Giove-A met its prime objective of demonstrating a Galileo navigation signal in space. • Giove-A already has been a remarkable success, and it will enable ESA to achieve their 4 major objectives with this satellite at relatively low cost. • The Galileo system is on its way!