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A Heat Switch has been developed, namely a device able to autonomously regulate its own thermal conductance in function of the equipment dissipation and environmental heat sink conditions. It is based on a Loop Heat Pipe (LHP) technology, with a passive bypass valve which diverts the flow to the Compensation Chamber when needed for regulation purposes. The target application is the potential use on a Mars Rover thermal control system. The paper recalls the Heat Switch design, and reports the results of an extensive test campaign on the ground demonstrator. The performance of the device was found extremely satisfying, and often exceeded the system requirements.

The Automated Transfer Vehicle (ATV) is a European Space Agency (ESA) servicing and logistics transportation system for the periodic re-supply of the International Space Station (ISS). The ATV will be launched by Ariane 5 and will provide the following services to the ISS: refuelling of the ISS (transfer of fuel from ATV to the station), reboost of the ISS (increasing the station’s orbit altitude, using the ATV’s propulsion system), delivery of cargo such as compressed air, water and pressurised payloads to the station, destruction of waste from the station. The ATV is composed of the so-called Spacecraft (SC) and an Integrated Cargo Carrier (ICC). The Spacecraft includes the propulsion, reboost and attitude control systems, the avionics and the solar generator system.

The ESA Polar Platform, as part of the ESA Columbus Development Programme, is scheduled to be launched as single passenger by an Ariane 5 vehicle in mid 1998. The multimission platform is designed to accommodate a wide range of payload complements to be flown on a series of missions in order to satisfy the growing future earth observation needs in continuation of the current ERS programme. Multi-mission capability is achieved by design modularity wherever feasible and cost-effective. This paper describes the thermal control design of the Polar Platform which follows its modular configuration and which has to cope with a wide range of generic performance parameters, whilst being adaptable to provide optimised performance for specific missions. Special thermal control features are highlighted as the software and hardware controlled heater systems, thermal doublers using carbon / carbon material and the battery compartment heat pipe radiator.

The Automated Transfer Vehicle (ATV) is a European Space Agency autonomous, expendable logistic transportation system for Low Earth Orbit. The ATV will be launched by Ariane 5 and its mission is to contribute to the logistic servicing of the International Space Station: via the delivery of a cargo (crew items, scientific experiments, spare parts..) as well as of fluids such as propellant, water and compressed air via the provision of an extra service consisting of retrieving the station wastes when departing (replacing the upcoming cargo) and getting rid of them through the final destructive atmospheric re-entry of the ATV itself via the contribution to the orbit control of ISS by providing a reboost and attitude control capability to the ISS. The ATV consists of a Spacecraft and an Integrated Cargo Carrier. The Spacecraft includes all subsystems necessary for the automated flight to the ISS and for the reboost, including the propellant tanks and the thrusters.

As part of the European contribution to the Russian segment of the International Space Station (ISS), the European Robotic Arm (ERA) is designed under contract of the European Space Agency by Fokker Space as the Prime contractor. The particularly challenging aspect of the ERA thermal design is to enable ERA operation under all possible in-orbit thermal environmental conditions which are to be experienced throughout its 10 year life. These conditions can be between extreme cold without sunlight for hibernation to extreme hot with ERA operating in full sunlight in close vicinity to a large station item, for instance, the solar arrays. First a short description of the ERA system is given with a summary of the main thermal design features. The system level thermal balance test on the ERA Engineering Qualification Model (EQM) is intended to validate the system level thermal model, which consists of the subsystem thermal models as supplied by the respective subcontractors.

Jules Verne (JV) is the name of the first Automated Transfer Vehicle (ATV) developed by ASTRIUM Space Transportation on behalf of European Space Agency (ESA). JV was launched the 9 March 2008 by ARIANE 5 and performed the 3 April 2008 its automatic rendezvous and docking to the International Space Station (ISS) to which it remained attached up to the 5 September 2008. In the meantime, JV has provided the ISS with dry and fluid cargo and performed one refueling, four ISS re-boosts and one Debris Avoidance Maneuver. JV completed its successful mission by offloading waste and was destroyed during its re-entry the 29 September 2008. Generally, development and verification of Power management rely on classical thermal and electrical engineering.

EADS SPACE Transportation has developed and qualified under ESA contract the Refrigerator/Freezer Rack (RFR) for use by NASA on-board the ISS. This paper will present a general overview of the RFR system design, the qualification test results and an outlook to potential future usage of the RFR.

For experiments with plants and other organisms in microgravity, a facility with a life support and an observation system, both of them operating by remote control on a centrifuge rotor, is deemed necessary. This would enable the scientist on ground to study development and behavior of organisms under microgravity and different acceleration conditions in Space, also with the possibility of a permanent on-board 1-g control. ESA’s EMCS (European Modular Cultivation System) has been designed for these kinds of experiments, especially for long lasting plant cultivations from seed-to-seed. However, the experiment preparation, the design and testing of the experiment hardware and the ground reference need to be done in a ground model that accommodates all features of the flight model, but is adapted to the gravity conditions on ground. This model, called the ERM (Experiment Reference Model), was delivered to ESA in 2002 and has been submitted to extensive testing.

Temperature and humidity control are vital functions of an environmental control and life support system in a manned spacecraft. A MCHX Technology Demonstrator has been developed using hollow fiber membranes to remove heat and water vapor from the cabin air. The functional principle of the MCHX is based on micro porous hydrophobic hollow fiber membranes. Heat and water vapor are transferred through the membrane to the cooling the water. The water vapor will condense at the cooling water side. The technique promises a good alternative for the conventional noisy and power-consuming rotary condensate separator. This paper describes the MCHX development work including the rational for its concept, the module design and its performance data as a result of numerical predictions and a test campaign. The MCHX performance requirements are linked to those of the Columbus Laboratory, the European contribution to the International Space Station (ISS).

Two ESA facilities will be available for plant research and other biological experiments on the International Space Station: the European Modular Cultivation System (EMCS) in the US “Destiny” Module and BIOLAB in the European “Columbus” Laboratory. Both facilities use standard experiment containers, mounted on centrifuges and connected to life support systems, allowing telescience-controlled acceleration studies (0.001×g up to 2.0×g) and continuation of microgravity research on protoplasts, callus cultures, algae, fungi and seedlings, as earlier flown on Biorack, and new experiments with larger specimens of fungi, mosses and vascular plants.

Membrane gas absorption and desorption (MGA/MGD) for the removal of CO2 in manned spacecraft or other enclosed environment is subject of study by Stork and TNO for many years. The system is based on the combination of membrane separation and gas absorption. Advantage of this technology is that the system not only can be used to remove the carbon dioxide but also to control the relative humidity and temperature. Absorption of moisture and heat is achieved by cooling the absorption liquid below the dewpoint temperature of the gas stream. From the start in 1995, the Crew Transfer Vehicle is used as a basis for the design (1,2). Compared to the planned air conditioning system, consisting of a condensing heat exchanger, LiOH cartridges and a water evaporator assembly, MGA/MGD shows advantage in volume, mass and power consumption. The absorption liquid circulates through the spacecraft thermal control loop, replacing the coolant water.

For a planetary base, a reliable life support system including food and water supply, gas generation and waste management is a condition sine qua non. While for a short-term period the life support system may be an open loop, i.e. water, gases and food provided from the Earth, for long-term missions the system has to become more and more regenerative. Advanced life support systems with biological regenerative processes have been studied for many years and the processes within the different compartments are rather complete and known to a certain extent. The knowledge of the associated interfaces, the management of the input and output phases: liquid, solid, gas, between compartments, has been limited. Nowadays, it is well accepted that the management of these phases induces generic problems like capture, separation, transfer, mixing, and buffering. A first ESA study on these subjects started mid 2003.

Because of the reduction on the remaining Shuttle launches, the initial mission that was assigned for MELFI, the Minus Eighty degrees Celsius Laboratory Freezer for ISS, has been significantly modified. While the design was made for a MELFI flying 15 times over a period of 10 years with individual missions no longer than 2 years, present scenario requires to have MELFI in orbit up to 7 years. Extending the MELFI on orbit life from two to seven years has required staggered assessments, each of them aiming at preserving as much as possible the existing design. The potential life limited items are evaluated. On orbit maintenance will be extended for a longer period and maintenance activities foreseen initially to be done on ground between flights will be adapted for orbit. Degraded modes are evaluated so that MELFI ensures its mission at the end of the life even with some off-nominal conditions.

The MELISSA (Microbial Ecological LIfe Support System Alternative) project has been set up to be a model for the studies on ecological life support systems for long term space missions. The compartmentalisation of the loop, the choice of the micro-organisms and the axenic conditions have been selected in order to simplify the behaviour of this artificial ecosystem and allow a deterministic and engineering approach. In this framework the MELISSA project has now been running since beginning 1989. In this paper we present the general approach of the study, the scientific results obtained on each independent compartment (mass balance, growth kinetics, limitations, compound conversions,..), the tests of toxicity already performed between some compartments and their effect on the growth kinetics. The technical results on instrumentation and control aspects, and the current status of the ESA/ESTEC hardware are also reviewed.

The Minus Eighty (Degrees Celsius) Laboratory Freezer for the International Space Station (MELFI) is one of the freezers developed by ESA on behalf of NASA. Peculiar requirements for that facility are the long-term storage at low temperature, the rapid freezing of specimen to the required temperature, the large cold volume (300 l) and the low power consumption. To verify those requirements before the manufacturing of the flight hardware, a dedicated test campaign was performed on a ground model. This paper will start with a system overview, showing the main features of MELFI. The test set-up as well as their results will be presented and discussed, with particular emphasis on the methods used to predict the on-orbit (0-gravity) behaviour, by avoiding the sample internal convection and dewar internal convection during the test execution.

Membrane gas absorption for the control of CO2 in manned spacecrafts is studied by Stork and TNO. Membrane Gas Absorption (MGA) is based on the combination of membrane separation and gas absorption. The cabin air of a spacecraft is fed along one side of a hydrophobic membrane. The air diffuses through the membrane and the CO2 is selectively absorbed by an absorption liquid. Experiments showed that the MGA system can not only be used for the removal of the carbon dioxide but also can be applied to control the relative humidity and temperature of the cabin atmosphere. Absorption of moisture and heat is achieved by cooling the absorption liquid below the dewpoint temperature of the gas stream. This paper deals with the design aspects of a MGA system for combined CO2, humidity and thermal control aboard the Crew Transfer Vehicle. Furthermore, design data are presented for a similar system aboard the International Space Station.

In a harmonized ESA/NIVR project the performance of membrane gas absorption for the simultaneous removal of carbon dioxide and moisture has been determined experimentally at carbon dioxide and humidity concentration levels representative for spacecraft conditions. Performance data at several experimental conditions have been collected. Removal of moisture can be controlled by the temperature of the absorption liquid. Removal of carbon dioxide is slightly affected by the temperature of the absorption liquid. Based on these measurements a conceptual design for a carbon dioxide and humidity control system for the Crew Transport Vehicle (CTV) is made. For the regeneration step in this design a number of assumptions have been made. The multifunctionality of membrane gas absorption makes it possible to combine a number of functions in one compact system.

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.

The Hubble space telescope (HST) solar array consists of two identical double roll-out wings designed after the Hughes flexible roll-up solar array (FRUSA) and was developed by the European Space Agency (ESA) to meet specified HST power output requirements at the end of 2 years, with a functional lifetime of 5 years. The requirement that the HST solar array remain functional both mechanically and electrically during its 5-year lifetime meant that the array must withstand 30,000 low-Earth orbit (LEO) thermal cycles between approximately +100 and -100 °C. In order to evaluate the ability of the array to meet this requirement, an accelerated thermal cycle test in vacuum was conducted at NASA's Marshall Space Flight Center (MSFC), using two 128-cell solar array modules which duplicated the flight HST solar array. Several other tests were performed on the modules.

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.