Search Results

CryoSat is the first satellite of ESA's Living Planet Programme realised in the framework of the Earth Explorer Opportunity Missions. CryoSat is a radar altimeter mission dedicated to determine trends in the ice masses of the Earth. The overall spacecraft configuration was driven by the budget constraints applicable for the opportunity mission, the high inclination orbit with drifting orbit plane and the stringent stability requirements for the radar altimeter antennas. Innovative thermal design solutions were needed for the following items: The instrument antennas have to comply with very stringent pointing stability requirements. The star trackers need to be mounted at a thermally adverse position and still have to be maintained on low temperature levels.

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 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.

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).

In 1995 the European Space Agency did award a C/D Contract for the design & development of an ECLS Subsystem for the Multi Purpose Logistics Module (MPLM) to Astrium’s ECLS ‘Center of Competence’ that built the ECLSS for Spacelab already. Actually first MPLM modules were successfully flown to the ISS with the Astrium built ECLSS qualified as ‘excellent’ by the crew having asked permission to sleep in there. In parallel the design and development of an ECLS for Europe’s Columbus module did commence and is actually close to completion. In view of the above a broad set of qualified and even space proven ECLS equipment is now ‘on-hands’ to thoroughly compose respectively derive the ECLS subsystems of future applications e.g. HabModule, CRV and Space Hotel at a limited delta design and validation effort thus fitting into the tighter financial budgets of the manned space programs to come.

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.

The Herschel satellite is a space based telescope designed for the investigation of sub millimeter radiation from astronomical objects. The cryogenic system is an essential part of the telescope’s Extended Payload Module (EPLM). The cryogenic system has to provide an environment of sufficiently low temperatures to assure the proper functioning of the scientific payload. Main component of the cryogenic system is the cryostat, a huge vacuum vessel (see: Figure 1) with various cryogenic components inside. In order to qualify the components of the cryogenic system, multiple tests such as leak tests, thermal cycle tests, pressure cycle tests and vibration tests are performed. In this paper the test program for two cryo components, the rupture disc and a safety valve is discussed. The testing philosophy is presented and selected results of tests at ambient and low temperatures are shown.

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 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.