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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.

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.

Astrium investigates Methane Pyrolysis in the perspective of long-duration exploration missions. In particular this process, which recovers Hydrogen from Methane, allows reaching the maximum closure level of the Air Revitalization System ARES. Past studies were reviewed in the light of today's technical advancement and a technology trade-off, supported by bread boarding, is performed. Current activities do concentrate on Critical technology selection and feasibility demonstration including bread boarding and testing, Methane Pyrolysis Assembly (MPA) operational interfaces with ARES Potential applications of MPA for other exploration capabilities, like in-situ resources utilization (Moon and Mars) The paper presents the achievements so far.

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.

Astrium investigates Methane Pyrolysis in the perspective of long-duration exploration missions. In particular this process, which recovers Hydrogen from Methane, allows reaching the maximum closure level of the Air Revitalization System ARES, see figure 1. Past studies as presented in ref. /1/ had been reviewed in light of today's technical advancement and a technology trade-off, supported by bread boarding, resulting in the pre selection of the plasma technique to perform the Methane Pyrolysis. In parallel two methods for plasma provision are investigated: Direct Current Plasma, sustained by a discharge arc rotating in a nozzle to supply energy to the flowing through carrier gas. Micro Wave (MW) Plasma, sustained by a MW within a Quartz tube embedded in a MW resonator cuboid Study activities did concentrate on Development testing of pre selected plasma Pyrolysis technology.

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.

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.

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.

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.