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NIRSpec is a near-infra-red spectrometer and one of the four instruments onboard the James Webb Space Telescope (JWST). The JWST observatory will be placed at the second Lagrange point (L2). The instrument will be operated at about 30 Kelvin. Temperature stability and controlled heat rejection to dedicated JWST radiators are important issues of the NIRSpec thermal design. Besides thermal insulation, the NIRSpec Optical Assembly Cover also has to provide light tightness and stray light suppression to prevent unwanted light entering the instrument. Air tightness is needed to allow a controlled purge gas flow for contamination prevention while allowing proper air venting during launch. Because of mass constraints a cover employing two-foil Kapton blankets supported by aluminum posts and a wire tent was chosen. Failure tolerance and cleanliness are other important design drivers. This paper describes the design solutions established to fulfil the contrary requirements

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.

An orbital flight test program for a fixed alkaline electrolyte (FAE) electrolyser stack is planned to be performed in September 2003 on board a Spacehab mission. The flight experiment is supposed to demonstrate the readiness of the FAE technology as one essential component to close the oxygen loop on board the ISS by means of an Air Revitalization System, ARES. The paper describes the design of the experiment, the current development status and the intended test program in space and shows its programmatic relation to ARES.

The current ECLS baseline of the International Space Station ISS contains an open oxygen loop. Breathable oxygen, generated by electrolysis of water, is supplied to all habitable modules. The crew of max. 7 astronauts converts the oxygen into metabolic carbon dioxide, which needs to be removed from the ISS atmosphere. Adsorption of CO2 is achieved through molecular sieves, desorption of CO2 is conducted by evacuation into space. This open process needs approx. 1500 kg of water upload mass annually. More than 75 % of this upload mass can be saved, if the open oxygen loop will be closed. This paper outlines the closed loop air revitalization system of Astrium, ARES, which has been successfully tested in closed chamber tests. It demonstrates in detail the technical application of ARES on ISS and outlines the commercial benefits. The second part of the paper describes ARES for a Mars habitat with a closed oxygen and hydrogen loop.

In the range of the Columbus Orbital Facility (COL) program, the European contribution to the International Space Station (ISS), DASA Dornier developed and qualified four new supporting devices for the Environmental Control and Live Support System (ECLSS) as listed below: 1. The Vacuum & Venting Pressure Sensor (VVPS). Based on the Pirani principle, it utilizes the pressure dependence of the gas thermal conductivity. 2. The Humidity Sensor (HS) provides information for the Thermal & Humidity Control System (THC). It works according to the dew point principle, guaranteeing a long stability over at least 10 years. 3. The Air Flow Sensor (AFS), working according to the hot wire anemometer principle, is dedicated to identify low air flow conditions. 4. The Waste Gas Line Shut-Off Valve (WLSOV), a DC motor driven ball type vacuum valve, was adapted to the space station requirements (e.g. noise and micro-g).