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Instrument SOVAP ( IRMB A. Chevalier pour S. Dewitte)

Flight operations Right shutter status Temperatures Forbidden modes of operation Conclusion. Instrument SOVAP ( IRMB A. Chevalier pour S. Dewitte). Présentation of SovaP. BOlometric Sensor (Observatoire Royal de Belgique). DIARAD (radiomètre différentiel absolu)

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Instrument SOVAP ( IRMB A. Chevalier pour S. Dewitte)

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  1. Flight operations Right shutter status Temperatures Forbidden modes of operation Conclusion Instrument SOVAP( IRMB A. Chevalier pour S. Dewitte)

  2. Présentation of SovaP BOlometric Sensor (Observatoire Royal de Belgique) DIARAD (radiomètre différentiel absolu) (Institut Royal de Météorologie de Belgique)

  3. Flight operations • Launch 15 June 2010 • SovaP Operations : • 29/06/2010 Close the shutters from the CCC. • Succession of commands Rad01; Rad10; Rad04; Rad06 With TM0 • 03/07/2010 Mode A09 (Double close alternate L/R) (outgassing with shutters closed) • Start of the Bolometric measurements • Mux tables 0,9,5,0 (First voltage calibration of the acquisition chains data analysis) • Electrical power equilibrium check and passive thermal balance check (R03; R21; R02) • 19/07/2010 Consistency check prior Solar acquisition (R03; R21; R02) and A09 • Mux tables 0,9,5,0 (Second voltage calibration of the acquisition chains prior to solar acquisition) • 21/07/2010 Start of Diarad Solar acquisition (A03,A02,A03) • A04 Compensation mode .. Symmetry check • R17;R14;R16;R04 Passive thermal response check Integrity of detectors • A03; A13; During this sequence, first occasional failure of right shutter. (Tod = 27°C) • Due to the shutter failure, decision to leave the initial plan and to switch to R04; R06 • 06/08/2010 Test of active right operations under IRMB supervision (A03) • 09/08/2010 All shutters closed (R05) due to abnormal right shutter operation • 28/08/2010 Monthly Left cavity measurement (Reference channel for ageing A02) • A14 Double open Closed L/R Check to double the capacitors banks charge prior movement. • A04 Compensation mode L/R Check of simultaneous operations of both shutters • 21/09/2010 Try to open right (failed) and monthly left acquisition • 28/09/2010 Power OFF • 30/09/2010 Power On Try to open right (failed) • 06/10/2010 Monthly Left measurements • 27/10/2010 Try to open right (failed) and monthly left measurement • 09/11/2010 Try to open right during stellar mode (failed) R06 the 10/11/2010 • 18/11/2010 Successful right shutter operation • 19/11/2010 Monthly Left measurements with new routine A08

  4. Right shutter status • Temporal behaviour of the status and analysis • On the base of the succession of the shutters status each ten seconds we have defined three state at the beginning of R10 (Nominal Open right) • +1: Movement without bounce (First 10 sec status : open) • 0: Open with bounce (First 10 sec status not open, not closed), (20sec status Open) • -1: Bounces then close : (First 10sec status : moving, second status bounced back closed) • Traceability of the actuators (design, fabrication) certified by Thales • We see that we never pass from the +1 to the -1, the open with bounce is always a precursor of the failed close state. • On the left shutter we have never noticed bounces, we conclude there is no risk to have the same issue on the Left channel.

  5. Right shutter status

  6. The command of the actuators

  7. Right shutter status

  8. Right shutter status • The right shutter is open since the 18/11/10 at 03:01:30 • The reason is not totally clear but the new thermal model gives indices of sign change of the thermal gradient. • The request to have a modified A03 procedure with on board check of the status is cancelled • We will keep the right shutter open until a specific scientific request ask to close it. • For the time being any command implying to close this shutter is forbidden.

  9. Temperatures

  10. Picard at Yasny

  11. Differences between the two shutters

  12. The VIRGO shutters

  13. Right shutter temperature

  14. Virgo heritage

  15. Place of the temperature sensors

  16. Forbidden modes of operations • Due to the lack of reliability of the right shutter it is decided to let it open • This decision will be maintained till the data treatments have validated the A08 operations. • As a consequence, the following radiometric modes are forbidden : • R00 ; R01 ; R02 ; R03 ; R05 ; R06; R09 ; • R11 ; R13 ; R14 ; R17 ; R18 ; R19 ;R20 ; • R21 ; R22 ; R23 • The allowed radiometric modes of operation are : R04 ; R07 ; R08 ; R10 ; R12 ; R16; R17 • The automatic modes allowed are A08 ; A10 • This new situation gives a push to use the mode A08 for the first time in space ! • Consequence : opportunity to have helioseismologic data with SovaP • cross check the non-equivalence of radiative and electrical energy in the different mode of operation. • Consequence : after the data analysis from an objective point of view, redefinition of the modes of operation and optimization of the voltage calibration scheme will be done for end of February. • Objective analysis implies the budget of what is gained in precision at different calibration periodicities against what is gained in signal noise ration and sampling rate.

  17. Commissioning feedback - Conclusions • Most of the anomalies noticed at delivery to CNES and during commissioning are the consequence of the lack of availability of qualified technical resources at RMIB incompatible with the work load. • Noise on channel 4 • This noise reduce the performances of this channel and impact the right detector / cavity measurements of this channel. The procedure of data treatment has been adapted to minimize the impact on the performances (Counts2Volts.exe version 2.2). This impacts redundancy. • The PI has accepted the instrument with this defect because the performances are sufficient to reach the scientific objectives and the design has proved his immunity to single failure. • RMIB (with the cooperation of Latmos) has prepared a document with the scientific performances budget in the foreseen scenario of operation (Routine A03, monthly monitoring of ageing with A02), but the data treatment is in phase lag to the real orbital operations. • Some uncertainty margins evaluated according to ISO 17025 will be larger than those announced in PIC-NT-S-7-SOV-6000-IRM Ed1 Rev1 (Performances scientifiques) • Commissioning before failure has allowed to acquire enough data in the classical modes of operation and with the double open periodicity. • The right shutter failure gives a push to satisfy more the helioseismologic community but reduce accurate TSI sampling rate. • The use of A08 for the first time in space will increase the instrumental science output. • We have still the opportunity to reduce the total SovaP power budget with the R12, A08 sequence. • The PI will define the new scientific objectives in accord with the flight hardware status and is enthusiast of the perspectives of the DIARAD-BOS cooperation in SovaP

  18. Conclusion • Thanks to the SovaP team which supported the investigations during commissioning . • Thanks to LATMOS for supporting our investigations and specially Mustapha Meftha et JP Marcovici. • Thanks to CNES and the thermal experts.

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