Search Results

COROT mission is managed by CNES (French National Space Agency) in association with three major French laboratories (LAM, LESIA, IAS) and several European countries, contributing to the payload and the ground segment. This astronomy mission objectives are astero-seismology as well as planet finding. The COROT spacecraft is based on a PROTEUS low Earth orbit recurrent platform, developed by CNES and Alcatel Alenia Space. It was injected on 27th December 2006 at a 898 km polar and circular orbit by a Soyuz launcher and is being operated from CNES-Toulouse. This paper focuses on the thermal control design and first in-orbit performances of the payload which mainly consists in an afocal telescope, a wide field camera with cooled CCDs, and an equipment bay. Largely using standard and well-proven technologies, this paper also points out some thermal control specificities and techniques used.

The INTERnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) is an ESA observatory scientific satellite which was successfully launched on the 17th of October 2002. The payload consists in four instruments : an optical camera (OMC), a X-ray monitor (XRM), an imager (IBIS) and a spectrometer (SPI). The spectrometer (20 keV-8 MeV energy range, 2.3 m high, 1.1 m diameter, around 1300 kg) has been supplied by CNES where this instrument has been managed, assembled and tested before delivery to ESA for satellite level activities. This paper describes the spectrometer flight model thermal design achieved thanks to the different international partners, gives and overview of the cryostat used to cool down the detection plane and exposes the thermal validation plan used at instrument level (thermal mathematical model and thermal test philosophy, cryostat thermal validation). We then focus on in-flight performances and compare them to expected ones.

This paper describes the thermal balance test which has been performed on the spectrometer SPI Structural and Thermal Model (INTEGRAL project) from August 27th to September 17th 1999. Main SPI modes have been simulated in order to qualify the instrument thermal control. MLI efficiency has been measured, as well as thermal conductance to the payload module (PLM). For this, a specific thermal adaptator (a mechanical frame and two aluminum plates regulated by two cryostats) has been developed and will also be used for thermal vacuum tests of the SPI Flight Model. This thermal adaptator and its behavior during thermal balance test are described.

One of the current applications for cryogenic heat pipes is the European astronomy satellite INTEGRAL where two aluminium / ammonia axially grooved heat pipes will be used to transport a heat load of 20 W from an intermediate stage at 210K to a radiator. A prototype heat pipe of 1.65m long, with a 14 mm outside diameter, has been manufactured and tested. The extrapolated 0g maximum heat transport capability at 200K is 60 W.m. Tests have shown the reliability of the ammonia heat pipe to work close to its freezing point (down to 197K) and its ability to thaw within a few minutes using the right procedure. A development model with the same heat pipe profile but filled with ethane has shown a maximum heat transport capability of 19 W.m at 200K under 5 mm adverse tilt (46 W.m for the ammonia) and just a few watts at ambient temperature. This confirms the suitability of the ammonia heat pipe for the INTEGRAL application, where the operating temperature is [200K;300K].