Search Results

Necessity of thermal control of dissipative units located on the earth panel and thermally linked to the North and South radiators of a telecommunication satellite has been identified since many years ago. The thermal control of TV SAT TDF platforms was defined using this concept, but necessitated a complex heat pipe networks with on-ground test constraints. The emergence of the capillary-pumped two-phase loop authorises to perform the same function using one item with virtually no on-ground test constraints. Since 1995, Alcatel Space Cannes (formerly Aerospatiale Cannes), sponsored by CNES, have developed a STENTOR (“Satellite de Télécommunication pour l'Expérimentation de Nouvelles Technologies en Orbite”) 1000 W CPL. The ground qualification has been completed in 1999 and the flight qualification is planned late 2000 (launch of STENTOR satellite).

Deployable radiators (DRs) have been in development at Alcatel Space Cannes (formerly Aerospatiale Cannes) since the 1980s to respond to the increasing need of additional heat rejection area. In 1980-1985, Alcatel Space Cannes, sponsored by Centre National d'Etudes Spatiales (CNES), defined, manufactured and ground-tested a 250 W thermal rotating joint DR. Since 1995, Alcatel Space Cannes, sponsored by CNES, have developed a STENTOR («Satellite de Télécommunication pour l'Expérimentation de Nouvelles Technologies en Orbite») 600 W Loop Heat Pipe (LHP)-based DR. The ground qualification will be completed mid 2000 and the flight qualification is planned late 2000 (launch of STENTOR satellite). Late 1998, Alcatel Space, co-funded by the European Space Agency (ESA), started the development of a Deployable Lightweight High Performance Radiator (DELPHRAD). The 1200 W DR will be ground-tested by mid 2001.

CNES's involvement in research work into space cryogenics began at a very early stage. METEOSAT's passive cryogenic radiator was designed by CNES around 1970. Work on mechanical cryogenic machines began around 1985 with theoretical studies. The first basic mock-ups were made in 1990 for Vuilleumier and Stirling cycle machines. This work led to the completion in 1993 of two breadboards (CEA/CENG and L'AIR LIQUIDE). During this time, CNES developed a space experiment for the OMEGA project using a Stirling machine in the tactical class which was subject to a qualification cycle specially designed for the project. In order to promote very low-temperature astronomy experiments, CNES began the space qualification of a cooler developed by the CNRS/CRTBT in Grenoble. This system uses the dilution of helium 3 in helium 4 to lower temperatures from 4 K to 0.1 K. A temperature of 4 K can be obtained either with a helium bath or a mechanical cryogenic machine.