The new ESTRACK Santa Maria Ground station for support of Ariane 5 launch of ATV. Head of Systems and Project Support Section

The Santa Maria Station is presented by: Part 1 Boris Smeds OPS-GSY Overview of requirements and technical implementation Specific differences compared to a conventional satellite ground station Lessons learned, unexpected problems and how they were solved Part 2 Gerhard Billig OPS-ONV Test and validation Operational concept, preparations and launch operation

Part 1 Boris Smeds OPS-GSY

Overview of requirements and technical implementation

Specific differences compared to a conventional satellite ground station

Lessons learned, unexpected problems and how they were solved

Part 2 Gerhard Billig OPS-ONV

Test and validation

Operational concept, preparations and launch operation

Requirements Receive telemetry data from Ariane 5 during the launch of ATV and send to Kourou in real time. Cover the passes over the Atlantic region. Santa Maria Azores

Receive telemetry data from Ariane 5 during the launch of ATV and send to Kourou in real time.

Cover the passes over the Atlantic region.

Time scale of actual implementation. April 2006: Site Inspection June 2006: SoW for antenna and related equipment. ITT September 2006: PDR for antenna, TM system and power plant November 2006: CDR for antenna and TM system March 2007: Start of Factory Acceptance Tests April 2007: Shelter and TM equipment installation at Santa Maria July 2007: Commissioning of Powerplant October 2007: Start of antenna commissioning at Santa Maria December 2007 / January 2008: Antenna fully validated for AR5

April 2006: Site Inspection

June 2006: SoW for antenna and related equipment. ITT

September 2006: PDR for antenna, TM system and power plant

November 2006: CDR for antenna and TM system

March 2007: Start of Factory Acceptance Tests

April 2007: Shelter and TM equipment installation at Santa Maria

July 2007: Commissioning of Powerplant

October 2007: Start of antenna commissioning at Santa Maria

December 2007 / January 2008: Antenna fully validated for AR5

Station system overview

X-band option To allow reception of Earth observation satellites in the 8025-8400 MHz band the antenna is equipped with a dual feed and dichroic sub-reflector.

To allow reception of Earth observation satellites in the 8025-8400 MHz band the antenna is equipped with a dual feed and dichroic sub-reflector.

Major differences compared to satellite RF-links Dual frequency transmission. One antenna on each side of the spinning launcher Telemetry modulation: frequency shift (not CCSDS) , no remnant carrier. 1 Mbps No Kepler orbit during launcher propulsion phase. Continuous position updates that may have large errors. High angular velocity due to close distance ( 180 km , 7 km/s) Communication using HDLC protocol ISDN and Inmarsat satellite link to Kourou

Dual frequency transmission. One antenna on each side of the spinning launcher

Telemetry modulation: frequency shift (not CCSDS) , no remnant carrier. 1 Mbps

No Kepler orbit during launcher propulsion phase. Continuous position updates that may have large errors.

High angular velocity due to close distance ( 180 km , 7 km/s)

Communication using HDLC protocol

ISDN and Inmarsat satellite link to Kourou

Existing concrete platform

Equipment shelter and Telemetry kit Reuse existing design of TM-kit developed for Ariane tracking network by Carlo Gavazzi Space

Reuse existing design of TM-kit developed for Ariane tracking network by Carlo Gavazzi Space

Calibration tower Guests on existing tower at Pico Alto

Guests on existing tower at Pico Alto

Antenna supplied by Indra Espacio. Assembly at factory. Partly new design. 5.5 m dish, Carbon fibre

Partly new design. 5.5 m dish, Carbon fibre

Antenna installed at Santa Maria X-Y mount (no singularity at zenith) Inmarsat antenna Radio link to calibration tower

X-Y mount (no singularity at zenith)

Murphy’s law If anything can go wrong, it will.

If anything can go wrong, it will.

Filters required to reject UMTS ( mobile phone ) Filters supplied from US company. Delayed delivery due to ITAR Receive band

Filters supplied from US company.

Delayed delivery due to ITAR

Unexpected problems, wrong paint. Glossy paint was used on the reflector. Feed cover burnt when pointing to the sun during G/T tests. Repainting of reflector required

Glossy paint was used on the reflector. Feed cover burnt when pointing to the sun during G/T tests.

Repainting of reflector required

Unexpected problems, autotrack patterns Error in computer simulation of antenna pattern for the autotrack feed. Actual pattern gave larger angular offset than expected. Original feed design

Error in computer simulation of antenna pattern for the autotrack feed. Actual pattern gave larger angular offset than expected.

Unexpected problems, autotrack patterns Computer simulation

Computer simulation

Antenna tracking pattern measured Error signal

New feed New feed design solved the issue. 4 lateral dipoles closer together. Sum signal generated by combining signals from the lateral dipoles.

New feed design solved the issue.

4 lateral dipoles closer together. Sum signal generated by combining signals from the lateral dipoles.

Antenna tracking pattern new feed Error signal

Unexpected problems, bad cables RF cables after Low noise amplifier with 60 dB gain with damaged screen. ( Cut through at manufacturing and covered so not visible ) Caused the receive system to self oscillate at 2.2 GHz. Leaking cable

RF cables after Low noise amplifier with 60 dB gain with damaged screen. ( Cut through at manufacturing and covered so not visible )

Caused the receive system to self oscillate at 2.2 GHz.

Unexpected problems. RFI from microwave link Microwave links at Azores used the same frequencies as foreseen for Ariane 5. Local coordination possible. Microwave links could move to other frequencies.

Microwave links at Azores used the same frequencies as foreseen for Ariane 5.

Local coordination possible. Microwave links could move to other frequencies.

Unexpected problems. Broken RF cables. Cables from antenna are passing over a cable chain that is bent up to 180 degree each pass. Selected coax cables had solid centre conductor not suitable for repeated bending. Cables replaced , first temporary with RG223 available on site. After AR5 support replaced to RG214 High Flex cables.

Cables from antenna are passing over a cable chain that is bent up to 180 degree each pass.

Selected coax cables had solid centre conductor not suitable for repeated bending.

Cables replaced , first temporary with RG223 available on site.

After AR5 support replaced to RG214 High Flex cables.

Servo system not optimised Large pointing errors when tracking moving targets. Servo system software corrected

Large pointing errors when tracking moving targets.

Servo system software corrected

Rough climate conditions. Rust Replace bolts with better quality, and repaint

Rust

Replace bolts with better quality, and repaint

Useful tool for maintenance