OTHERS

COROT

he CNES-led COROT (COnvection ROtation and planet Transit) mission has two objectives: measure the stellar seismic activity and contribute to the research of exo-planets (planets outside the solar system). Both require a very challenging instrument to detect extremely small signal variations over long periods of time.

SODERN has developed two pieces of equipment for this program:

• a focal plane which includes 4 CCD detectors operating at a temperature lower than ­-40°C and featuring a very accurate temperature stability,
• a dioptric objective lens which is placed at the output of the afocal telescope and then projects the image of the observed part of the celestial vault onto the detectors.

DECLIC

Research on supercritical fluids has been performed in micro-gravity with ALICE CNES instruments on the Russian MIR station. ALICE1 and ALICE2 were operated on board MIR from 1992 to 2000 and have demonstrated the interest of such research.

After having delivered both ALICE optical systems, SODERN has developed the experimental drawer of the DECLIC instrument that will be installed in the International Space Station.

The DECLIC optical bench is a complex and automatic microscope used to observe and measure phase transitions of water in a so-called "supercritical" state or directional solidification of specific alloys within high temperature and high pressure conditions.

EM MEGHA-TROPIQUES

CNES has selected SODERN for the development of the Electronic Modules of both SCARAB and SAPHIR instruments.

SCARAB and SAPHIR are parts of the CNES contribution to the MEGHA-TROPIQUES satellite developed together with the Indian space agency (ISRO). MEGHA-TROPIQUES is devoted to the atmospheric research: SPAHIR is a 6 channels microwave radiometer for the retrieval of water vapour vertical profiles and horizontal ditribution, and SCARAB is a radiometer dedicated to the measurements of outgoing radiative fluxes at the top of the atmosphere.

The Electronic Module operate communications between the instruments and the spacecraft, and also perform scan mechanisms control and temperature measurements with very high accuracy.

Two Electronic Module are provided, each one operating instrument dedicated application software.

Electronic Module Design : Power Conversion Board, Processing Unit board (ATMEL LEON 2, ACTEL RTAX1000/2000), Mechanisms Command/Control board,

The re-use of a very powerful processing unit allows for SCARAB and SAPHIR instruments control with a high level of performances.

Scan mechanisms are controlled through a digital loop operating innovative algorithms whose efficiency has been proved for two different configurations. Indeed, SCARAB abd SAPHIR instruments use very different mechanisms (resolver for SCARAB and optical encoder for SAPHIR) and in both cases control performances proved out to be far beyond the requirements with a rotation accuracy of few 1/100°.

The SCARAB Electronic Module is also in charge of the modulator (chopper) control in parallel of all other activities.

Electronic Module overview : Mass : 8,5 Kg (including 5mm alu shielding), Dissipated power : SCARAB : [24 ; 31] W, SAPHIR : [27 ; 37] W. Dimensions : 230 x 310 x 117 mm3, Electrical interface : 1553 bus.

The development of the MEGHA-TROPIQUES Electronic Module has started in 2006 and Flight Models delivery is foreseen before the end of 2008.

Both high compacity of the modules and high performances level make this design easily adaptable to other missions.