E. Tilmans 34 April 2003 Page 1

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Mission operations at Redu

• Ground Segment Overview.
• Pass Operations.
• Satellite Operations.
• Payload Operations and products availability.
• CHRIS products summary

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• Ground Segment Overview

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• Small S-band terminal
• Main Characteristics
• WaveLab (/Gigacomp) manufacturer
• Dish of 2.4 m diameter.
• Az. 0-360 deg, El. 3.35-176 deg.
• up to 5 deg/sec.
• Program track.
• 2200 - 2290 MHz receive band.
• 8.6 dB/K G/T.
• 2025 - 2110 MHz transmit band.
• 42 dBW EIRP
• RHCP both receive/transmit.
• 70 MHz IF.

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• Base Band Equipment
• Main Characteristics
• ENERTEC 3801-20
• PM / BPSK, PSK receive demodulation.
• Up to 1 Mbits/s in BPSK without subcarrier
  receive data rate.
• Viterbi decoder, REED-SOLOMON decoder,
• CRC checker receive link coding.
• Telemetry function CCSDS TM packet compliant
  with virtual
• channel demultiplexer,packet reconstruction.
• Data delivered to client at either frame or
  packet level.
• PM, FM / PSK, FSK transmit modulation.
• PSK 10 kbits/s (4 kbits/s) transmit data rate.
• CCSDS TC packet compliant telecommand function.
• Network interface TCP / IP.
• Telemetry recording on internal hard disk.

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• EGSE Mission Control System (EMCS)
• Main Characteristics
• SUN Ultra 60.
• SCOS II with specific extensions developed
• for automated procedures
• Parameter Interface,
• Command Interface,
• Flight Dynamics Interface (FDIF),
• Telemetry Parameter Print (TMPP).
• Support of PUS services.
• Satellite TM/TC history files online.
• Satellite TM/TC database
• 486 TC, 2477 TM parameters.
• Pass template uses the Operations Automation
  Environment. OAE allows the complete
• automation of the system and handling of
  predetermined anomalies.
• Control procedure scripts uses automated
  procedures built in Test Preparation Execution
• Environment and Tcl scripts.

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• Mission Planning System / Mission Data server
• Planning of the satellite passes (STK COTS).
• Local archiving of the mission products, the S/C
  processed TM ready for analysis and
• the pass operations results, with partial
  mirroring to the Web server through the firewall.

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• Web server

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• Maintenance Operations and Archive system
• Back-up operations.
• System services monitoring
• disk space, telnet, ftp, etc
• Satellite Simulator
• SVF

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• Pass activities
• Setup and control of the ground station and the
  TM/TC Base Band Equipment (BBE).
• Uplink of TCs, monitoring of RT HK TM (VC7),
  download of mission data (TM store and PPU data).
• Data playback from the BBE (filing of the store
  TM HK in the SCOS (VC0) , extraction of the PPU
  data (VC1)).
• Reports generation with some sent by email TMPP,
  FDIF, TC Ver Log, Ops Log
• Data transfer on the MDS to be available by
  mirroring mechanism on the Web site.

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• Pass phases
• Preinit phase AOS 17 min Get Update TLEs
  (ESOC http server NORAD priviledged access)
• Get Update Az/El file for next 10 days
• Preparation phase AOS 15 min Start STK
• Setup BBE
• Get TX LOS times
• Setup Start antenna controller
• Setup Start spectrum analyser Doppler
  frequency setup
• start SCOS
• BBE_Connect
• BBE TC test
• Note OAE allows exit error code which
  determines the status of the dependency status
  between boxes linked together.

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• Pass phases
• Contact phase AOS
• Reset PTD redundant
• Init AD
• Disable power safe mode Set VC1 70 RT HK TM ON
• Dump Context memory PPU dump operations Health
  Check
• Clear CHRIS config slots
• AOB memory dump
• dump HK TM store 4
• OBET coarse check
• RF scheduling
• dump TM store 1, 2, 3 by TC schedule
• Uplink CHRIS request using TC schedule
• Uplink CHRIS dump request using TC schedule
• AOB TC procedures

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• Pass phases
• LOS phase Health check
• TC schedule readback
• RT HK TM OFF
• Uplink OFF
• Post Pass phase BBE recording off
• BBE TM/TC disconnection
• Playback VC7 RT
• Playback VC0 store
• Playback VC1 PPU
• Extract images
• TC procedures list print
• Print Logs
• Process Context memory
• HK TM store TMPP
• HK RT TMPP
• OpsLog and TC Ver report
• CHRIS TMPP

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• Pass phases
• Logging phase Pass OK/NOK
• Start NextPass
• Cleanup phase Get BBE session
• Check BBE response
• MOA
• Update Web TM
• Spare area spare tasks RF, POWER, DHS, AOCS,
  GS, RAM patches, Payload.

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• Satellite Operations Orbit Characteristics
• Polar Sun Synchronous Orbit
• 21 March 2003
• RAAN 159 deg. (1036 solar time descending
  node).
• Incl. 97.8 deg.
• SMA 6985.452 km. Based on one year of TLEs,
  SMA has decreased by 10 km in 16 months
• Period 96 min 50 sec
• Arg. Per 342 deg.
• Satellite Operations Groundstation visibilities
• TM/TC operations performed solely from the ESA
  Redu ground station.
• Pass selection criteria minimum 300 sec above 5
  deg. Elevation including the horizon
• mask. Typically, 2 morning and 2 evening passes.
• Satellite Operations Mission Control System
  Characteristics
• The satellite control system allows full
  automated passes . This mode of operations is
• always used outside of the normal working hours

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• Satellite Operations Satellite modes
• Quiescent mode.
• Bdot mode Magnetic mode minimization of the
  variation of the magnetic vector in the body
  frame. Hardware RW, MM, MT. Safe mode. ACNS
  software NAV_MAG, GDC_BDOT, CTL_BDOT.
• Terrestrial mode Nadir, High power, Fixed
  target, Imaging. Hardware RW, MT, ST, GPS.
• Celestial mode Inertial frame or Sun frame.
  Hardware RW, MT, ST.
• ACNS submodes Sliding, Angular momentum
  management, control gains adaptation.

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• Payload operations
• SREM Usually switched on in Terrestrial mode.
  The scientific data are automatically downloaded
  from the TM store 3, extracted and placed on the
  web server on a 5 days basis.
• DEBIE Usually switched on in Terrestrial mode.
  The scientific data are automatically downloaded
  from the TM store 3, extracted and placed on the
  web server on a daily basis. Additional data are
  also made available DEBIE external temperature,
  AOCS mode, filtered quaternion values.
• CHRIS The CHRIS imaging session (5 pictures) is
  entirely controlled by the on board PPU manager
  which ensures the synchronization between the
  manoeuvre controlled by the AOCS manager and the
  pictures timeline. The inputs to the telecommand
  procedure is then limited to
• The coordinates of the target (Long, Lat, Alt,
  max roll)
• The configuration of the CHRIS instrument
• The selection of additional HK TM in order to
  improve the observability.
• The telecommand procedure is entirely inserted in
  the on board command scheduler.
• The current operations scenario allows typically
  1 CHRIS scene per day. The main operational limit
  is coming from the size of the CHRIS product (80
  MB for 129 MB reserved in the MMU) and the number
  of ground station passes.

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• Payload operations
• HRC/WAC The fixed target manoeuvre is controlled
  by the AOCS manager while the pictures timeline
  is done by direct commanding to the PPU unit. The
  inputs to the telecommand procedure is then
  limited to
• The coordinates of the target (Long, Lat, Alt)
  and max roll angle
• allowed
• The time of the pictures
• The configuration of the HRC instrument
• The selection of additional HK TM in order to
  improve the observability.
• The telecommand procedure is entirely inserted in
  the on board command scheduler.
• Experiments PASS, MRM, SIP.

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• Summary of CHRIS Sira requests uploaded
  completed including sun and dark.
• July 27 (60 images including 16 dark).
• August 19 (63 images including 7 dark).
• September 28 (35 images including 23 dark).
• October 28 (92 images including 9 dark).
• November 21 (54 images including 6 dark).
• December 28 (125 images including 10 dark and 10
  sun).
• January 32 (248 images including 5 dark and 19
  sun).
• February 16 (75 images including 4 dark and 1
  sun )
• March 13 (54 images)