Paris 15-16 may 20061

HELLO

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SIAMOIS in Dome-C

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Paris 15-16 may 20062

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).

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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).

Paris 15-16 may 20064

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

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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.

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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.

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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.

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The Bonnette and the telescope.

Telescope

Motors

Science signalIn the optical fiber

Guiding system

Control loop

Optics

Dichroic

Paris 15-16 may 20069

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.

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The optical bench.

O1 : Interferometer Objective M1 : Plan MirrorO2 : Camera Focus Objective M2 : Steps Mirror (∆l)M4 et M3 : Segmentary Mirror L1 : Beam SplitterL2 : Delay component R1 et R2 : Grating

400mm

320mmO1

O2

L1L2

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Signal on the Camera

Science spectra

CC

D R

ows

nm

Calibration lines

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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.

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The mechanical structure.

Interféromètre SIAMOISJP Amans, GEPI, Obs Paris

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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).

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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).

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The command/control system.

Guiding systemThermal control

systemCamera and HK

Commande/controlsystem

HK

HK : T°,PWMCommand : T°, PWM

ImageHK (T°, P)Exposure, windowing

Raw storageBackup

Pre-processingIHM

Quick-LookData sending

Paris 15-16 may 200617

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!

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Development planning

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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.

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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.

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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!

Paris 15-16 may 200622

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!

Paris 15-16 may 200623

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€.

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Budget and funding

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Buget and funding (the laste one)

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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!

Paris 15-16 may 200627