Post on 11-Jan-2016
description
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
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
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)
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
Proton fluxHeavy ion LETspectrum
Total dose B
Total dose AElectrons &deep charging
MerlinSpace Weather Monitor
CEDEXSpace Weather Monitor
Giove-A Experimental Payloads
• GPS Receiver – SSTL
• Laser Retro-Reflector
Laser Retro-Reflector Array
SSTL Miniature Space GPS Receiver
CEDEX Radiation Monitor
MERLIN Radiation Monitor
GPS Receiver Antenna
Giove-A Payload Architecture
AleniaAntenna
Upperband
Lowerband
CEDEX MERLIN
Payload RF Section TM/TCnode
SatellitePlatform
Tx0Tx1
Rx0Rx1
CAN
CAN CAN
CAN
Payload RF Section TM/TCnode
CAN
MEO GPSReceiver
LaserRetro-reflector
CAN
CFI
Environmental payload
Experimental payload
SSTLNSGU Interface
CAN
1553
Alcatel EspacioClock Monitoring &
Control Unit(CMCU)
TM/TC B
10.23MHz 10MHz 10MHz
TM/TC A
TEMEXRubidium Atomic
Frequency Standard(RAFS)
TM/TC A
10MHz
TEMEXRubidium Atomic
Frequency Standard(RAFS)
TM/TC B
10MHz
SSTLNavigation Message
Generation Unit(NMGU)
CAN 1553
SSTL Modulator,Frequency Generator &
Upconverter Unit(MFUU)
CAN 10.23MHz
Dupper
Dlower
E5a,b
E6
E2L1E1
E5a,b E6 E2L1E1
CA
MP
1C
AM
P210.23MHz
DigitalClock
Splitter
SSTLCFI Interface B
CAN
TM/TC
SSTLCFI Interface A
SSTLCFI Interface A
CAN
TM/TC
TW
TA
TW
TA
Coupler
CouplerDiplexer
E2L1E1
E5a/b
E6
LabenNavigation SignalGeneration Unit
(NSGU)
1553 1553 TM/TC B
122.76MHz
TM/TC A
NorspaceFrequency Generation& Upconversion Unit
(FGUU)
TM/TC B
122.76MHz
10.23MHz
TM/TC A
• Payloads: Navigation, Environmental and Experimental
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
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
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.
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...
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!