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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.

An advanced trace gas monitoring system for long duration manned space missions - such as the International Space Station - is discussed. The system proposed is a combination of a Fourier-Transform Infrared Spectrometer (FTIR) and a distributed ‘Smart Gas Sensor system (SGS). In a running multi-phase programme [1,2] the FTIR technology, applying novel analysis methods, has been demonstrated to handle multi-component gas measurements, including identification and quantification of 20 important trace gases in a mixture. In the current phase 3, initiated end of 1997, a fully operational FTIR technology demonstration model will be manufactured and tested. The SGS consists of an array of twenty electrically conductive polymer sensors supplemented with an array of quartz crystal microbalance sensors. The technology has been tested on the Russian MIR space station and is currently miniaturized into a second-generation flight model.

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.

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.

The Closed-Loop Air REvitalisation System ARES is a regenerative life support system for closed habitats. With regenerative processes the ARES covers the life support functions: 1. Removal of carbon dioxide from the spacecraft atmosphere via a regenerative adsorption/desorption process, 2. Supply of breathable oxygen via electrolysis of water, 3. Catalytic conversion of carbon dioxide with hydrogen to water and methane. ARES will be accommodated in a double ISPR Rack which will contain all main and support functions like power and data handling and process water management. It is foreseen to be installed onboard the International Space Station (ISS) in the Columbus Module in 2013. After an initial technology demonstration phase ARES shall continue to operate thus enhancing the capabilities of the ISS Life Support System as acknowledged by NASA [5]. Due to its regenerative processes ARES will allow a significant reduction of water upload to the ISS.

In a multiple-phase ESA project starting in 1990, the technology for trace gas monitoring in a crewed space cabin was developed. Based on optical principles - a Fourier-Transform-Infrared Spectrometer in combination with sophisticated analysis S/W - the instrument has the characteristics to identify and quantity quasi on-line over 30 most relevant trace gases in air. A system for testing the analysis technology in a shuttle flight is presently under design. The ANITA (Analyzing Interferometer for Ambient Air) development status and plans for the space flight beginning of 2003 will be reported in this paper. The description of the analysis S/W was already reported in an earlier ICES paper [1].

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.

In an earlier assessment of trace gas monitoring techniques it was shown that Fourier Transform Infrared Spectroscopy (FTIR) is the most promising technology for multicomponent gas analysis of the breathing air for long duration crewed space missions. It has the potential of meeting all the requirements established for the different trace gas monitoring scenarios; however, it needs further development. An important step to achieve this development objective is the breadboarding of such an FTIR system with particular emphasis on the critical technologies. The critical technologies as identified so far are the detector and cooler, the gas cell, the infrared source, and the analysis software. In this paper we will present and discuss the relevant requirements, the planned instrumental and software concept to be realized for meeting the intended monitoring task, and the expected performance data of the breadboard. The work is being performed under ESA contract.

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.

The cabin space of the Columbus APM is well ventilated by air entering through multiple air diffusers and exiting via the return grid and hatch. Therefore, the heat transfers by bulk fluid motion and by convection to the walls need to be experimentally and/or numerically investigated and implemented in the thermal mathematical models (TMM) describing the cabin. CFD analysis provided key data on the thermal couplings due to convective heat transfer and bulk fluid motion for the thermal mathematical model, which in turn was used to correlate test data from an environmental control system test and to provide supplemental information on assumptions used in the lumped capacitance model. This paper presents the logic and results of the steady-state CFD analysis, the potential implementation of the results in a thermal mathematical model, and compares these results with test data obtained during a separate Columbus cabin ventilation qualification test.

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.

A final test activity was carried out to complete the verification of the Environmental Control System (ECS) performances by experimentally reproducing the thermal hydraulic behaviour of the Environmental Control & Life Support Subsystem (ECLSS) section integrated in the overall Module, expected on analytical basis. A previous test campaign (called Columbus ECS PFM Test) carried out in EADS-Bremen in spring 2003 and described in paper number 2004-01-2425 showed some contradictory data concerning the air loop behaviour. These incoherent test results were related to the environmental and geometrical cabin loop conditions during the on-ground 1g test and to improper position of the sensor measuring the cabin temperature. For this reason a partial repetition of the test has been performed. In particular, this experimental campaign was focused on the verification of the cabin air temperature control, as a consequence of the Temperature Control Valve (TCV) movement.

At the 2002 ICES, FAVORITE, the orbital flight experiment for a fixed alkaline electrolyte (FAE) electrolyser stack was presented. The planning at that time was to fly the experiment in September 2003 on board the Space-Hab mission STS-118 with the space shuttle COLUMBIA flight ISS-13A.1. Due to the tragic accident of COLUMBIA on Feb. 1st, 2003, these plans became obsolete and alternative launch opportunities were looked for. They were finally found with the unmanned Russian FOTON-M2, which is built by TsSKB-PROGRESS in Samara, Russia and scheduled for launch from the Baikonur cosmodrome in April 2005. Because of the switch from a manned to an unmanned mission and other operational constraints, FAVORITE had to be redesigned in several parts. This paper summarizes the objectives of the flight experiment and describes the required design changes. It also presents an overview of the actual development status as well as of the work ahead.

This paper presents the status of ongoing BB studies for an optimized trace gas monitoring (TGM) system configured to simultaneously and quasi-online detect (quantitatively and qualitatively) 30 different trace gases in manned spacecraft. The system principle relies on the detection of molecule absorption lines in the infrared being converted into a measured spectrum by a Fourier Transform Infrared (FTIR) Spectrometer. The work is based on 10 years study phases aiming now towards performance demonstration on unknown gas mixtures and an in-flight demonstration on Space Shuttle or ISS. The theoretical background, sensor combinations, SW principle descriptions and multi-module monitoring strategies have been reported earlier (please refer to reference [1] - [4], [6]).

In this paper, an advanced trace gas monitoring system for manned space cabins is presented. The principle of functioning of the measurement system is based on the detection of gas-specific absorption features in the Infrared area of the spectrum. The core element in the monitoring system is a Fourier-Transform Infrared (FTIR) Spectrometer. When calibration is carried out applying sophisticated, novel analysis methods, the system can simultaneously detect and quantify all the interesting gases in manned space cabins. In a previous Trace Gas Monitoring multi-phase program (TGM 2) [1],[2], the FTIR technology has demonstrated its ability to handle multi-component, quasi on-line gas measurements, including identification and quantification of 23 important trace gases in a mixture. In the ongoing phase 3 (TGM 3), initiated end of 1997 [3], a fully operational FTIR technology demonstration model is tested being able to detect simultaneously 30 different trace gases in a mixture.