Search Results

Alcatel Space Cannes has successfully designed, manufactured and ground tested a two-LHP lightweight and high performance deployable radiator (“DELPHRAD”) in the frame of a development program co-funded by ESA. DELPHRAD is a follow-up of the STENTOR deployable radiator flight experiment sponsored by CNES (“Centre National d'Etudes Spatiales”; French National Space Agency). The STENTOR and DELPHRAD LHPs were designed, manufactured and delivered by EHP Nivelles (formerly SABCA Brussels). DELPHRAD features significantly lower mass budget than that of STENTOR with slightly better thermal performance. The considerable mass improvement is achieved essentially by the direct condensation thermal concept and the use of corrugated flexible lines. Some technological innovations contribute to facilitate the deployable radiator thermal sub-system manufacturing and its integration in a satellite system.

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.

This paper presents the last developments which have been performed at SABCA under internal funding, and the application of this work on the Technological Telecommunication Satellite STENTOR. The High Performance Capillary Pumped Loop ( HPCPL ) has been defined to get a reliable operation mode under a very wide range of operation conditions. Preliminary results have been already presented (ref. (1)), showing the high performances and the reliable functional characteristics of the HPCPL. The present paper emphasises the last developments which have been performed at SABCA.

The paper presents the results of various SABCA activities in the field of two-phase heat transport, being a critical review and analysis of existing capillary pumped loops, the identification of the needs of future capillary pumped two-phase thermal control systems, the development of capillary evaporators, which incorporates nickel porous structures, that can provide a pumping pressure up to 38000 Pa, and the solving of the problem of capillary pump cavitation. These activities have led towards the development of a reliable multi-evaporator/condenser capillary pumped loop, which is discussed in details. A test loop configuration is described. The presented results of various tests clearly prove the viability of the concept for future applications. Proposed flight demonstrations are presented.

The Water Supply Assembly (WSA) is part of the Liquid Management Section (LMS) of the Hermes Environmental Control and Life Support Subsystem (ECLSS) (see ref. [1] and [2]). The WSA has to provide pure water for drinking and food preparation (rehydratation of dry food and beverage powder) and to provide pure water for hygiene purposes (oral hygiene and towel wetting). To obtain different desired temperatures (as well as different quantities of water to be dispensed), a heating device, using electrical foils, and a cooling device, using a water/water heat exchanger have been designed with regard to the critical mass and power requirements. Two dispensers are used to fill food/beverage or hygiene (towels) containers. As part of the Hermes C1 phase, breadboard models of the heating device (heater) and of the cooling device (chiller) have been manufactured and functionally tested.

This paper presents results of new development work carried out in the context of the Water Conditioning Assembly (WCA) which is part of the Liquid Management Section (LMS) of the Hermes Environmental Control and Life Support Subsystem (ECLSS) (see ref [1] and [2]). Its task is to condition and monitor the quality of highly pure water which has been produced in two fuel-cell stacks by the oxidation of hydrogen. This water will be used for different cooling elements (e.g. water evaporator, water sublimator) and as potable water for drinking and food purposes. The assembly consists mainly of: a hydrogen separator, providing for removal of dissolved and gaseous residual hydrogen from the fuel-cell water.