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This paper describes recent advances in MPB's approach to spacecraft thermal control based on a passive thin-film smart radiator tile (SRT) that employs a variable heat-transfer/emitter structure. This can be applied to Al thermal radiators as a direct replacement for the existing OSR (optical second-reflector) radiator tiles with a net added mass under 100 gm/m2. The SRT employs a smart, integrated thin-film structure based on the nano-engineering of V1-x-yMxNyOn that facilitates thermal control by dynamically modifying the net infrared emittance passively in response to the temperature of the space structure. Dopants, M and N, are employed to tailor the transition temperature characteristics of the tuneable IR emittance. This facilitates thermal emissivities below 0.3 to dark space at lower temperatures that enhance the self-heating of the spacecraft to reduce heater requirements.

An increasing number of spacecraft missions have very stringent requirements for thermal stability to avoid thermally driven noise from affecting the main observables. For example, it may be necessary to reduce temperature fluctuations in the neighbourhood of the instrument below micro-Kelvin (μK). Consequently, the influence of fluctuations in boundary temperature or internal power dissipation on temperature at the instrument detector must be precisely evaluated. Thermal stability requirements are usually expressed as an upper limit on the linear spectrum density (LSD) of temperature fluctuations. This indicates the strength of the response to a perturbation of a given frequency, and is usually stated in units of K/√Hz. The LSD can be estimated by running a succession of transient simulations and applying Fast Fourier Transforms techniques, but this method is time-consuming and has numerical limitations.

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.

Columbus is being built as the European contribution to the International Space Station (ISS) Program. The ECLS subsystem is developed by DaimlerChrysler Aerospace/Dornier under a contract from Alenia Aerospazio. This paper will survey the qualification test results of the Columbus cabin ventilation subjective test conduction up to February 2000.

European Space Agency (ESA) has planned two important missions for performing astronomical investigations in the infrared and sub-millimetre wavelength range: ♦Herschel satellite has an observatory type mission and is the fourth cornerstone mission (CS4) of the “Horizon 2000” programme. It will carry three instruments (HIFI, SPIRE, and PACS) for high and medium resolution spectroscopy, imaging and photometry over the sub-millimetre and far-infrared range. A 3.5 m telescope will focus the incoming radiation on the Focal Plane Units of these instruments. ♦Planck satellite has a survey type mission and is the third Medium mission (M3) of the “Horizon 2000” programme. It will provide a definitive high-angular resolution map of the cosmic microwave background anisotropies over at least 95% of the sky and over a wide frequency range. A 1.5 m telescope will focus the incoming radiation on the focal plane shared by the two instruments (LFI and HFI).

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 first use of the Polar Platform (PPF) is for the Envisat/PPF mission. The Envisat/PPF spacecraft has a launch mass of 8.5 tons and external dimensions of 10.0 metres x 2.8 metres x 2.1 metres. Due to it's large size it was necessary to perform the thermal balance and thermal vacuum testing in two modules. The first test was for the Service Module (SM) and the second for the Payload Module (PLM). This paper discusses the thermal balance testing and subsequent correlation of the Polar Platform Service Module thermal mathematical model.

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).

This paper describes the transient simulation of a single-phase mechanically pumped fluid loop (MPFL) thermal control system, developed in the frame of the European Space Agency ARTES 8 (Advanced Research in Telecommunication Systems - Large Platform Program) program. MPFL is intended to cool a part of the payload on a high power telecommunication satellite. A transient simulation has been implemented using ESATAN/FHTS; hence the results have been correlated with the test results, obtained from full scale MPFL testing, using real on-orbit profiles. The most considerable parts of the activities described herein are simulation of the thermal control law, verification of control parameters during thermo-hydraulic testing and the subsequent correlation.

This paper reports on the thermal testing of METOP (METerological OPerational satellite) Payload Module Engineering Model, conducted in May/June 2001 at ESTEC’s Large Space Simulator (LSS). The paper describes the logic for the selection of the test configuration, the test phases and the performed test sequences. The test results are presented and the correlation results between predicted and measured temperatures are discussed.

Given the constraints of the current launchers, manned exploration beyond LEO implies long time missions, a high mass of metabolic consumables and consequently regenerative life support technologies developments. To validate their efficiency, as well as their reliability, these technologies need to be tested in the most analog conditions (i.e. isolation, limited spare part, …). A large number of these conditions are met in the new permanent French-Italian settlement called Concordia, currently being built in the Antarctic continent. Over the last 15 years, ESA developed regenerative life support technologies. Two of these technologies: a Grey Water Treatment Unit and a Black Water Treatment Unit are currently assembled at the size of 15 to 70 persons to fulfill the Concordia crew needs The first technology is a multi step filtration system and will recycle the shower, washing machine, dish washer and cleaning water.

Metop (METeorological OPerational satellite) is a series of three satellites designed to monitor the climate and improve weather forecasting. This paper describes the thermal analysis, thermal testing performed, and relevant lessons learned. For the thermal analysis campaigns it focuses on: exchange and correlation of reduced thermal mathematical models established in various software formats sizes and content of the models, in particular automatic generation of reduced models from the detailed models uncertainties definitions of thermal interfaces The lessons learned from the thermal testing campaigns apply to: selection of test environment, using solar simulation and/or infra-red techniques selection of test cases based on thermal design driving parameters and/or test chamber capabilities adequate instrumentation (i.e. thermocouples, test heaters) for all critical components (un)expected events e.g.

A study of the first in-orbit temperatures of Huygens shows that the probe will very likely survive thermally all vacuum cruise and coast phases. Calculated heat fluxes, mass flows of Titan's atmosphere into and out of the probe and temperatures give confidence also for the mission phase proper in 2004 i.e. the 2.5 h descent into Titan's -2OO°C atmosphere. Basotect foam bags insulate the probe from this atmosphere. These bags and their fixation had drastically to be modified between Titan test on STPM (May 95) and on FM (June 96). The mission phases, thermal requirements, thermal design, tests with the probe, special tests for the foam bag development and their modification are presented.

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.

The forthcoming planetary missions require an autonomous crew habitation and a high mass of metabolic consumables. To minimise the launch mass and/or the logistic needs, these missions shall then be based on regenerative technologies able to obtain resources for the human life from the on board produced wastes, guaranteeing a high closure degree of the system. In this context ESA has promoted a preliminary study called SpaceHaven, to understand which functions must be guaranteed for a long term and autonomous mission and to investigate about the hardware/technologies to be exploited to meet the identified functions. A dedicated demonstration program is to be proposed when needed technologies are neither available in Europe nor currently covered by a dedicated technological development.

The Columbus Orbital Facility is being developed as the European laboratory contribution to the United States' led International Space Station programme. The need to exchange thermal mathematical models frequently amongst the Space Station partners for thermal analyses in support of their individual programme milestone, integration and verification activities requires the development of a commonly agreed and effective approach to identify and validate mathematical models and environments. The approach needs to take into account the fact that the partners have different model and software tool requirements and the fact that the models need to be properly tailored to include all the relevant design features. It must also decouple both programmes from the unavoidable design changes they are still undergoing. This problem presents itself for both active and passive thermal interfaces.

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

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.

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.