1. Paris 15-16 may 2006 1 HELLO SIAMOIS in Dome-C

2. Paris 15-16 may 2006 2 Overall Description Divided in four sub-systems : –A dedicated Telescope with its Bonnette (telescope guiding and fiber coupling). –An Interferometer and a Camera. –A structure for thermal and mechanical control. –A command/control software system. Divided in five laboratories : –GIGT from OMP (Observatoire Midi-Pyrennée). –LUAN from OCA (Observatoire Côte d’Azur). –IAS (Institut d’Astrophysique Spatiale). –LESIA from OPM (Observatoire Paris-Meudon). –CSIC from Institutode Astrofisica de Andalusia (in discussion). One associated private contractor : –SESO (Société Européenne de Systèmes Optiques).

3. Paris 15-16 may 2006 3 Overall Description Assignment of the tasks : –GIGT : Development of the Bonnette and associated test equipment. –LUAN : Telescope delivery and Antarctic instrumentation expertise. –IAS : Thermal design and support for the environment qualification. –LESIA : Global management, camera, electronics and optical bench deliveries. –CSIC : Command/control sub-system delivery (not confirmed).

4. Paris 15-16 may 2006 4 Overall Description Thermo-mechanical structure. Optical bench. Interferometer Camera Dedicated Telescope Bonnette Calibration Optical fibers : signal and calibration Command/control system: Acquisition,image processing … Vacuum pump

5. Paris 15-16 may 2006 5 The constraints. Small budget and short planning… High reability of the instrument : –Observation requirements : 90% of duty cycle. –Very difficult to fix anything at Dome C in Antarctica. Very easy to use : –Not easy set-up at Dome C in Antarctica (once again :-) ). –Wintering will insure a minimal maintenance. Rather hard environmental conditions : –Shocks and temperature (level and gradient) during transportation and storage. –Temperature, humidity and pressure during operation.

6. Paris 15-16 may 2006 6 The telescope. Functions/Specifications : –Collect the light with an effective pupil of 40cm (diameter) in the visible part of the spectrum. –Optimization of the reflectivity in the blue part 400-600nm of the spectrum. –FOV of 6arcs. –Track any target in a TBD*TBD ° in the sky. –Function in a temperature range of -80°C<T<30°C. Phase A solution : –Classical 16” telescope with an azimutal mounting. –External guiding with a dedicated system. –F/10 numerical aperture. –Customization of the structure and driving motors to sustain low temperature.

7. Paris 15-16 may 2006 7 The Bonnette Functions/Specifications : –To point a target and maintain the flux inside the optical fiber with a jitter lower than 1arcs and an aperture of F/4. –Used of the science target to realize the fine guiding. –Function in a temperature range of -80°C<T<30°C. –Allow the calibration of the interferometer in the optical bandwidth. –Interface the optical fiber with the telescope. Phase A solution : –Mechanical and software interfaces with the telescope. –Dichroïc plate to realized the guiding with the red part of the spectrum. –Used of an ADC to correct differential refraction in the air mass. –Used of an calibration system in the place of the science target. –Used of optics to adapt the telescope aperture.

8. Paris 15-16 may 2006 8 The Bonnette and the telescope. Telescope Motors Science signal In the optical fiber Guiding system Control loop Optics Dichroic

9. Paris 15-16 may 2006 9 The optical bench. Functions/Specifications : –Collect all the flux of the science target in the 400-560nm optical bandwidth. –Carry out a doppler sampling of the signal (over 5 points). –Realize a spectral dispersion of 1000. –Focus the spectra on a 2 dim detector. –Has no moving element. –Carry out a spectral calibration during the observation. Phase A solution : –Used of a Mach-Zender interferometer. –The interferometer part of the optical path is realized in one block of the same material (Zerodur). –Used of a step mirror (intrinsic path difference). –Used of a delay component to optimize the path difference. –Used of a second optical-fiber coupled to a spectral calibration source. –Used of different dioptric to feed the interferometer and focus on the camera. –Used of segmentary mirrors to separate the spectra.

10. Paris 15-16 may 2006 10 The optical bench. O1 : Interferometer ObjectiveM1 : Plan Mirror O2 : Camera Focus ObjectiveM2 : Steps Mirror (∆l) M4 et M3 : Segmentary MirrorL1 : Beam Splitter L2 : Delay componentR1 et R2 : Grating 400mm 320mm O1 O2 L1 L2

11. Paris 15-16 may 2006 11 Signal on the Camera Science spectra CCD Rows  nm Calibration lines

12. Paris 15-16 may 2006 12 The mechanical structure. Functions/Specifications : –To ensure positioning of the optics in reference to the interferometer.  l = 100µm –To ensure positioning of the interferometer inside the optical path. –To maintain a primary vacuum inside the interferometer part (10 -4 bar). –To insure stray light baffling. – To allow the change of the delay plate to optimize versus the science target. –To insure the re-positioning of the optical fibers with an accuracy of 50µm. –To isolate the optical bench from vibrations and shocks. –To allow the integrity of the optics during thermal cycling (-40°C/+25°C). Phase A solution : –Used of a specific structure. –Special design for the lens mounts.

13. Paris 15-16 may 2006 13 The mechanical structure. Interféromètre SIAMOIS JP Amans, GEPI, Obs Paris

14. Paris 15-16 may 2006 14 The thermal control. Functions/Specifications : –To insure a temperature around 20°C±1K during the operation. –To insure a temperature stability (inside the frequency domain) of the following parts : Optics except the interferometer : ±1K in temporal with spatial gradient of ±0.5K. Interferometer except the delay component : ±0.1K in temporal with spatial gradient of ±0.1K. Delay component : ±50mK in temporal with spatial gradient of ±50mK. Phase A solution : –Classical thermal control of the room. –Maximal thermal decoupling of the interferometer. –Poor thermal conductibility of the interferometer part. –Structure wrapped in nut shell and thermal inertia to filter the external fluctuations and minimize the convection. –Used of MLI to reduce the radiative exchange. –No internal or variable power source. –Used of an active thermal control if needed at the interferometer interface (filter conductive perturbations).

15. Paris 15-16 may 2006 15 The command/control system. Functions/Specifications : –Send command to the guiding system to acquire the target. –Send command to the camera (exposure time and windowing). –Send new parameters to the active control systems (if needed). –Acquire the image and the HK of the instrument. –Acquire the active control systems corrections. –Store all the data on hard drive. –Carry out pre-processing of the data. –Allow the users to have a quick-look during operation. Phase A solution : –Develop a specific software (but use some sub-system’s module). –Use of a RAID hard disk and make periodic back up (DVD). –Use of internet to have a quick-look from Europe (limited bandpass).

16. Paris 15-16 may 2006 16 The command/control system. Guiding system Thermal control system Camera and HK Commande/control system   HK HK : T°,PWM Command : T°, PWM Image HK (T°, P) Exposure, windowing Raw storage Backup Pre-processing IHM Quick-Look Data sending

17. Paris 15-16 may 2006 17 Development Philosophy. Step I : Establish all the requirements of the sub-systems and the interfaces between them. Step II : Develop the test benches and equipments, write the invitation to tender for the industrial contractors. Step III : Develop the sub-systems (industries and laboratories) or buy them directly when possible (budget and specifications). Step IV : Individual acceptance of each sub-systems. Step V : Environmental qualification. Step VI : Integration of the sub-systems together up to the instrument level. Step VII : End-to-end test in laboratory and on the sky, final setup. Step VIII : After transportation to Dome-C, simple integrity test. Some revue are foreseen during the project development. Like “space instrument” development : quality, management of configuration, documentation, revues… with limitations!

18. Paris 15-16 may 2006 18 Development planning

19. Paris 15-16 may 2006 19 Development planning. In 2006, the main activities are:  Development of a test-bed to validate the optical concept.  Drafting of the Needed Technical Specifications for the different sub-system.  Study of a preliminary design of the optical fiber, the bonnette, the software architecture and the Thermo-Mechanical structure.  Delivery of a commercial camera. In 2007, the main activities are:  To continue the studies conducted in 2006 to present a PDR in march-april 2007.  Detailed studies of the different sub-system of the instrument.  Launching of the industrial contracts and the achievements in the laboratories (mainly the equipments test).  Implementation of the equipments test and facilities in the different laboratories.  The main objective in 2007 is to achieved a PDR at the beginning of the year and a FDR at the end of the year to be able to launch to industrial contracts.

20. Paris 15-16 may 2006 20 Development planning In 2008 and 2009, the main activities are:  Validation, test and integration of the different sub-systems.  Integration of the interferometer and environmental qualification.  Implementation of the infrastructure at Dôme C (house, software interface, …).  Integration of the instrument.  End-to-end test on the sky.  Packaging and transport to Dôme C. In 2010, at the beginning of the year, the instrument is setup in the facilities at Dôme C and ready to work.

21. Paris 15-16 may 2006 21 Integration and Test Philosophy. Each sub-systems will be tested with its own equipment test at a defined level of representativeness. Environmental qualification will be performed case-by-case. Acquired qualification will not be performed again (telescope). Requirement is : “to not be destroyed”. Thermal cycling will be performed. No switch-ON or operations outside the nominal temperature range is foreseen. At each deliveries and before integration will be performed an acceptance test including documentation. A test plan will be write for the integrated instrument, for each sub- systems and also for critical components. Levels of accuracy of all the measurements will be established in accordance with the instrument scientist. A data base will be feed by the results of elementary and end-to-end calibrations. Great, that’s a space instrument!

22. Paris 15-16 may 2006 22 Integration and Test Philosophy No detailed or reduce mathematical models are required. The insurance quality will be reduced just over the lethal limit. Except for the Bonnette (if needed in military type) the electronics will be of commercial type. No rad-hard device. The software development will not be subjected to spatial laws (cold or hot redundancy, correction error code, specific FPGA, …). We accept manual reboot! No irradiation qualification will be performed. Mechanical qualification will be performed depending the vibration and shock levels given by the transportation. Minimal setup may be performed at Dome C, including the interferometer installation (base line). Arrghh, that’s not!

23. Paris 15-16 may 2006 23 Budget and funding. Total budget of the instrument : 860k€. Transportation and primary housing dealt with IPEV. Different sources of funding : –Agence Nationale pour la Recherche : 460k€. Main part. – CSA and Paris Observatory : 110k€ * 2. –PNPS : 40k€. Laboratories : 100k€. –SESO and industrial partner : 40k€. Distribution of the budget : –Optical bench = 300k€. –Mechanical and thermal control = 200k€ –Telescope and Bonnette = 110k€ –Camera, electronics and software = 45k€. –Mission and test = 90k€. –Miscellaneous and support = 115k€.

24. Paris 15-16 may 2006 24 Budget and funding

25. Paris 15-16 may 2006 25 Buget and funding (the laste one)

26. Paris 15-16 may 2006 26 Participation of the different laboratories GIGT : 4 * 20% and 3 * 10%. LUAN : 2-3 *10%, support in Antarctic instrumentation. IAS : 25%, Integration support, 18 months for external support. LESIA : 75%, 3 * 50%, Integration support, 1 Phd student, around 3-5 support in expertise (from 5 to 30%). The percentages are smoothed over the 4 years of instrument development… including 2006 where nearly nothing will be done!

27. Paris 15-16 may 2006 27