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In a harmonized ESA/NIVR project the performance of membrane gas absorption for the simultaneous removal of carbon dioxide and moisture has been determined experimentally at carbon dioxide and humidity concentration levels representative for spacecraft conditions. Performance data at several experimental conditions have been collected. Removal of moisture can be controlled by the temperature of the absorption liquid. Removal of carbon dioxide is slightly affected by the temperature of the absorption liquid. Based on these measurements a conceptual design for a carbon dioxide and humidity control system for the Crew Transport Vehicle (CTV) is made. For the regeneration step in this design a number of assumptions have been made. The multifunctionality of membrane gas absorption makes it possible to combine a number of functions in one compact system.

The Automated Transfer Vehicle (ATV) is a European Space Agency autonomous, expendable logistic transportation system for Low Earth Orbit. The ATV will be launched by Ariane 5 and its mission is to contribute to the logistic servicing of the International Space Station: via the delivery of a cargo (crew items, scientific experiments, spare parts..) as well as of fluids such as propellant, water and compressed air via the provision of an extra service consisting of retrieving the station wastes when departing (replacing the upcoming cargo) and getting rid of them through the final destructive atmospheric re-entry of the ATV itself via the contribution to the orbit control of ISS by providing a reboost and attitude control capability to the ISS. The ATV consists of a Spacecraft and an Integrated Cargo Carrier. The Spacecraft includes all subsystems necessary for the automated flight to the ISS and for the reboost, including the propellant tanks and the thrusters.

Final preparation and configuration of the Columbus module at the Kennedy Space Center (KSC) required the performance of system level tests with the Active Thermal Control System (ATCS). These tests represented the very last system level activities having been concluded on the Columbus module before handover to NASA for space shuttle integration. Those very last tests, performed with the ATCS comprised the final ATCS Leakage Test, the final calibration and adjustment of the Water Flow Selection Valves (WFSV) and Water On/Off Valves (WOOV) as well as a sophisticated ATCS Residual Air Removal test. The above listed tests have been successfully performed and test data evaluated for verification closeout as well as input delivery for operational Flight Rules and Procedures. Some of the above mentioned tests have been performed the first time hence, a succeeding lessons learned collection followed in order to improve the perspectives of future tests.

Membrane gas absorption and desorption (MGA/MGD) for the removal of CO2 in manned spacecraft or other enclosed environment is subject of study by Stork and TNO for many years. The system is based on the combination of membrane separation and gas absorption. Advantage of this technology is that the system not only can be used to remove the carbon dioxide but also to control the relative humidity and temperature. Absorption of moisture and heat is achieved by cooling the absorption liquid below the dewpoint temperature of the gas stream. From the start in 1995, the Crew Transfer Vehicle is used as a basis for the design (1,2). Compared to the planned air conditioning system, consisting of a condensing heat exchanger, LiOH cartridges and a water evaporator assembly, MGA/MGD shows advantage in volume, mass and power consumption. The absorption liquid circulates through the spacecraft thermal control loop, replacing the coolant water.

ECOSIM is a software tool for the simulation of Environmental Control and Life Support (ECLS) systems which has been developed for the European Space Agency. A preliminary model of the Hermes Air Management System has been developed during the ECOSIM testing in order to assess the functionality of the software and to verify its results with those obtained from previous simulation tools. The model represents the Hermes cabin with its crew and it includes submodels for the sub-systems performing the following functions: Temperature and Humidity Control. Total Pressure and Composition Control. Air revitalisation. The interactions between these different subsystem are taken into account by the model, while many of the previous simulations made assumptions to decouple the different subsystems (e.g: a constant cabin temperature has been assumed during cabin depressurization transients, to decouple the pressure control section from the air conditioning section).

The ESA Polar Platform, as part of the ESA Columbus Development Programme, is scheduled to be launched as single passenger by an Ariane 5 vehicle in mid 1998. The multimission platform is designed to accommodate a wide range of payload complements to be flown on a series of missions in order to satisfy the growing future earth observation needs in continuation of the current ERS programme. Multi-mission capability is achieved by design modularity wherever feasible and cost-effective. This paper describes the thermal control design of the Polar Platform which follows its modular configuration and which has to cope with a wide range of generic performance parameters, whilst being adaptable to provide optimised performance for specific missions. Special thermal control features are highlighted as the software and hardware controlled heater systems, thermal doublers using carbon / carbon material and the battery compartment heat pipe radiator.

The European Polar Platform is a remote sensing satellite with the primary objective, in the ENVISAT-1 P/L configuration, to monitor and study the earth and its environment. The platform thermal design is passive assisted by heaters. Externally mounted P/Ls are responsible for their-own thermal control and are required to be thermally decoupled from the platform. The P/L thermal design is largely dependent on their detectors required temperature and stability. A wide range of design solutions is found: Stirling cycle coolers, Peltier elements, passive radiant coolers, heat pipe radiators. This paper describes the overall thermal design of the platform and the P/Ls, the principles of the selected ENVISAT-1 P/L accommodation, the relevant P/L to platform I/F design solutions and outlines the platform and P/Ls thermal verification logic.

For a planetary base, a reliable life support system including food and water supply, gas generation and waste management is a condition sine qua non. While for a short-term period the life support system may be an open loop, i.e. water, gases and food provided from the Earth, for long-term missions the system has to become more and more regenerative. Advanced life support systems with biological regenerative processes have been studied for many years and the processes within the different compartments are rather complete and known to a certain extent. The knowledge of the associated interfaces, the management of the input and output phases: liquid, solid, gas, between compartments, has been limited. Nowadays, it is well accepted that the management of these phases induces generic problems like capture, separation, transfer, mixing, and buffering. A first ESA study on these subjects started mid 2003.

The electric current which circulates downwards in the Earth atmosphere results from the motion of positive and negative ions drifting in opposite directions under the influence of an electric field. A body such as a balloon or a gondola, moving upwards against the electric field collects an excess of positive ions, whereas a falling body, such as a water drop, may acquire a negative charge. In a similar way, parcels of hot and cold air ascending or descending in a cloud are selectively charged. This model is proposed as an explanation for the charge separation mechanism which takes place within thunderstorm clouds characterized by vigourous turbulence and convection.