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The launch and activation of ESA's Columbus module in early 2008 marked the completion of more than 10 years of development. Since then the Columbus ECLS is operating, including its major European ECLSS assemblies such as Condensing Heat Exchanger (CHX), Condensate Water Separator, Cabin Fans and Sensors. The paper will report the experiences from the first year of operations in terms of events, failures and lessons learned. Examples of this is the description of some off-nominal situations (such as Condensate Removal and IMV Return Fan failure, and relevant troubleshooting), and the preparation to Columbus Reduced Condensation Mode, as requested by NASA in order to minimize the crew time needed to empty Condensate Water Tanks in US Lab.

European Space Agency's (ESA's) Columbus module was launched on February 7, 2008. This marks the completion of more than 10 years of development. It is a major step forward for Europe in the area of Environmental Control and Life Support (ECLS) as Columbus contains several major assemblies which have been developed in Europe. These include the Condensing Heat Exchanger, Condensate Water Separator and the Cabin Fans. The paper gives a short overview of the system and its features and it will report the experiences from the initial activation and operations phase.

1 The Closed-Loop Air REvitalisation System ARES is a proof of technology Payload. The objective of ARES is to demonstrate with regenerative processes: the provision of the capability for carbon dioxide removal from the module atmosphere, the return supply of breathable oxygen within a closed-loop process, the conversion of the hydrogen, resulting from the oxygen generation via electrolysis, to water. The ARES Payload is foreseen to be installed - in 2012 - onboard the ISS in the Columbus Module. The operation of ARES - in a representative manned microgravity environment - will produce valuable operational data on a system which is based on technologies which are different from other air revitalization systems presently in use. The ARES Technology Demonstrator Payload development started in 2003 with a Phase B, see references [1], [2], [3] and [4]. ARES is presently in Phase C1 and a PDR is scheduled for the beginning of 2009.

During the last years extensive work has been done to design and develop the Closed-Loop Air Revitalization System ARES. The potential of ARES e.g. as part of the ISS ECLSS is to significantly reduce the water upload demand and to increase the safety of the crew by reducing dependence on re-supply flights. The design is adapted to the interfaces of the new base lined Russian MLM module as possible location for a future installation of ARES. Due to the lack of orbital support equipment and interfaces to a waste water bus, to a feed water supply line and due to the availability of only one single vent line it was necessary to make the ARES process water loop as independent as possible from the host vehicle. Another optimization effort was to match the CO2 desorption profile with the available hydrogen flow to achieve a sufficient water recovery performance, while meeting all related safety requirements, minimizing complexity and improving reliability.

EADS SPACE Transportation GmbH designed, built and tested a condensate buffer to be located between a Condensing Heat Exchanger (CHX) and a Condensate Water Separator Assembly (CWSA), as part of the ECLSS of the European Columbus Module. Under zero-g conditions, the separation of water from an air-water mixture is always difficult, especially if a passive device is to be used such as the low power consuming Columbus CWSA. The additional buffer volume reduces condensate water peaks reaching the CWSA to a level that excludes an overloading of the CWSA and a release of free water droplets into the air return to the cabin. In the CHX/CWSA system this may only be necessary under worst case operational conditions and with a failure of the qualified hydrophilic coating of the CHX. The buffer design principle was confirmed via prior analyses and on-ground testing. The performance of such a condensate buffer under micro-g conditions was verified during parabolic flights.

During the last years extensive work has been done to design and develop the Closed Loop Air Revitalization System ARES. The potential of ARES for future space exploration missions is to significantly reduce the water upload demand, increase the safety of the crew by reducing dependency on re-supply flights and, due to the launch mass restraints, make future exploration missions to other planets possible. The ARES demonstrator includes the functions of CO2 concentration, CO2 reduction and oxygen generation. Whereas in previous phases ARES was designed to operate in NODE3 of the ISS, this has been changed to an intended ARES operation in the Russian Multifunctional Laboratory Module MLM. This year’s activities concentrated on process optimization of the Carbon Dioxide Removal Assembly (CCA) interaction with the Sabatier Reactor (CRA), extreme conditions testing, life time tests with the Sabatier Reactor and the oxygen generation stack and system testing.

Under an ESA Contract EADS SPACE Transportation GmbH has designed and built an advanced Stainless Steel Condensing Heat Exchanger (CHX) Spare as part of the Environmental Control and Life Support Subsystem (ECLSS) of the European Columbus Module that shall be docked to the ISS in early 2007. Lessons learnt from both, ground and space applications of condensing heat exchangers were to be considered, for risk mitigation, in a CHX alternative design. The slurper section is equipped with a sophisticated capillary suction feature that supports an adequate condensate removal and transport through the slurper holes to the water separator assembly even at low airflow condition. The air fin surface is covered with a hydrophilic coating that did pass qualification for 10 years' exposure to the various contaminants specified respectively determined in the ISS atmosphere so far. The biocidal additive of such coating is qualified for fungus growth prevention, accordingly.

FAVORITE (Fixed Alkaline Electrolyte Electrolyser Water Vapor Oxygen Reclamation In-flight Technology Demonstration Experiment) is an orbital flight experiment for a fixed alkaline electrolyte (FAE) electrolyser stack dedicated to generate oxygen and hydrogen out of water for life support and other applications. It was originally planned to fly in September 2003 on board the SpaceHab mission STS -118 with the space shuttle COLUMBIA flight ISS-13A.1, but after the tragic accident of COLUMBIA it was adapted to be launched with the unmanned Russian FOTON-M2 in May 2005. FAVORITE was therefore redesigned, manufactured and ground tested in 2004. This paper summarizes the pre-flight ground test results, reports on the lessons-learnt and gives an overview of the intended in-orbit and post-mission test program.

During the last years extensive work has been done to design and develop the Closed Loop Air Revitalization System ARES. The potential of ARES for future space exploration missions is to significantly reduce the water upload demand, increase the safety of the crew by reducing dependency on re-supply flights and due to the launch mass restraints - make future exploration missions to other planets possible. Past years’ activities concentrated on the development of a full-scale demonstrator which was in form, fit, and function comparable to an ‘engineering model’ (EM). Most equipment was off-the-shelf and has been mechanically upgraded to EM standard. The demonstrator includes the functions of CO2 concentration, CO2 reduction and oxygen generation. All components fit into one ISPR. The design minimizes the number of external interfaces in order to achieve a high degree of independence and flexibility. Design baseline for the development was the accommodation in NODE 3 of the ISS.

During the last years extensive work has been done to design and develop the Closed Loop Air Revitalisation System ARES. The potential of ARES e.g. as part of the ISS ECLSS is to significantly reduce the water upload demand and increase the safety of the crew by reducing dependency on re-supply. The current activities concentrate on the development of a full-scale demonstrator with ‘engineering model’ quality. The demonstrator will include the functions of CO2 concentration, CO2 reduction and oxygen generation. All components will fit into one ISPR. The design will minimize the number of external interfaces in order to achieve a high degree of independence and flexibility with respect to accommodation on the ISS. The paper describes the current development status and touches on critical technology tests for performance optimization.

During the last years extensive work has been done to design and develop the Closed Loop Air Revitalisation System ARES. The potential of ARES e.g. as part of the ISS ECLSS is to significantly reduce the water upload demand. The current activities concentrate on the development of a full-scale demonstrator with ‘engineering model’ quality. The demonstrator will include the functions of CO2 concentration, CO2 reduction and oxygen generation. All components will fit into one ISPR. The design will minimize the number of external interfaces in order to achieve a high degree of independence with respect to accommodation on the ISS. The paper describes the current development status and touches on critical technology tests for performance optimization.

Gas-water separation is a fundamental requirement during long term operation of manned and man-tended space systems. Two areas of specific concern are in cabin humidity and temperature control and in gas removal from cooling water loops. This paper addresses design and testing of breadboard models for a condensate separator and a gas trap. Both models are based on semi-permeable membranes as main functional elements. The breadboard designs are driven by the requirements of the COLUMBUS space station. The condensate separator shall remove heat as well as water vapour from a humid air flow. Water shall permeate through the membranes, that are separating the air from the cooling water. The gas trap shall filter gas bubbles in a water loop and release the gas from the loop. In addition it shall maintain dissolved gas levels well below saturation.

A summary of an ESA/ESTEC sponsored technology research programme is given aiming at the development of a CO2 partial pressure sensor suitable for monitoring the PP CO2 inside the oxygen ventilation loop of the EVA life support module. At first, a trade-off of candidate sensor concepts is presented. As result, the infrared optical sensor concept has been selected. In the frame of a discussion on basic facts of IR absorption the rationale for the selected configuration of the IR sensor is given. A breadboard model of the PP CO2 sensor together with a test set-up has been established. The sensor was subjected to a test programme consisting of two separate test periods. The main results are given. Finally, the findings are discussed in the light of the development of future flight hardware.

Temperature and Humidity Control are important functions for the astronaut's comfort and safety in an EVA Space Suit. Several sources within the suit, like electrically powered devices, the CO2 removal system and the astronaut himself are permanently producing heat and humidity. Both have to be removed in order to prevent visor fogging and overheating of the astronaut. Heat from the European Space Suit will be dissipated by the physical process of water sublimation. At pressures lower than 6 hPa water will directly transform from ice into vapor. In the Sublimator this process will take place within a porous plate and will remove heat from both the oxygen ventilation loop and the cooling water loop. The Sublimator thus consists of a porous plate with the feedwater distribution underneath and a liquid/gas heat exchanger part. A breadboard model has been fabricated from stainless steel and a new porous plate has been developed.

A European Extra-Vehicular Activity (EVA) System is being developed by the European Space Agency (ESA) as part of its Hermes Programme, with the primary objective of providing a manned intervention capability for external servicing of the Columbus Free Flying Laboratory. The development phase started in 1988. A major design driver for the EVA system is the required level of failure tolerance, to ensure the achievement of sortie objectives and crew safety. The failure tolerance requirements placed on the EVA system may be summarised as follows: no single failure should result in sortie abort, and a safe return to the Hermes “safe-haven” should be possible following a second failure. This paper presents possible design solutions to this requirement, in particular for life support and associated functions. The failure tolerance characteristics of existing American and Russian EVA systems are also examined for comparison.