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Two-phase capillary loops are being extensively studied as heat collection and rejection systems for space applications as they appear to satisfy several requirements like low weight, low volume, temperature control under variable heat loads and/or heat sink, operation under on ground and micro gravity conditions, simplicity of mounting and heat transfer through tortuous paths. In 1998–2000 Alenia defined and Lavochkin Association developed the Deployable Radiator on the base of honeycomb panels, axial grooved heat pipes and Loop Heat Pipe. It was designed for on-ground testing.

The COLUMBUS Attached Pressurized Module (APM) is the European orbiting laboratory which will be permanently attached to the International Space Station Freedom (SSF). It is designed to provide a range of laboratory facilities in a microgravity environment for payload experiments originating from the international payload-user community. The individual payloads will in general be mounted in payload racks which can be accommodated in fixed positions on the left and right hand sides of the laboratory and in the ceiling. International standard payload racks (ISPR) can be located in any of the SSF laboratory elements and find compatible interface conditions subject to agreements made between the international partners (NASA, NASDA and ESA). The APM design provides a water cooling capability by means of moderate temperature (MT) and low temperature (LT) pumped fluid loops. The cooling loops serve both the APM essential subsystem equipment as well as the payload users.

Every kind of human activity in space is made at least different on often more difficult by the peculiarity of the environment, characterized by the almost complete lack of gravity. It is difficult to realize, when staying with our own feet firmly on ground, how life could be altered by the absence of the ever present force of gravity! Among all the psychological faculties directly affected by microgravity, easy and quick orientation, and object identification (as they depend on the visual environment) are analyzed. This work follows on from previously published work (cf. ICES '91) by the authors, highlighting the importance of sensible groundrules in color choice for a space environment, to optimize the above-mentioned capabilities, to which crew performance reliability and safety are directly linked.

The Columbus Attached Pressurised Module (APM) Active Thermal Control System (ATCS) water loop collects the APM waste heat and transfers it to the Space Station Freedom (SSF) Central Thermal Bus (CTB). The interface between the APM water loop and the SSF ammonia loops is achieved with two ammonia/water interloop heat exchangers (IH/X), one being low temperature (LT) and the other moderate temperature (MT). The APM internal water loop provides cooling to payload and subsystem users which have varying temperature requirements at their heat rejection interfaces, and can be categorized as cold branch and warm branch users, (e.g. condensing heat exchanger (CHX) and refrigerator are cold branch users, while Avionic heat exchanger (AHX) and furnace payloads would be warm branch users.)

Manned Space Systems are usually designed to support the crew atmospheric conditions equivalent to those at sea level. In phases with frequent Extra Vehicular Activities (EVA), a reduced pressure environment is preferable to facilitate the EVA suit prebreathing procedures. The Columbus Attached Pressurised Module (APM) will face both pressure scenarios during its life. Operation at different pressure levels primarily affects the performance of the Environmental Control System (ECS) of the pressurised elements. A lower air density results in reduced heat exchange, adversely affecting both the crew comfort and the electronics air cooling. This paper reports the results of a study performed to identify the constraints and the numerous potential problem areas related to APM operations at reduced pressure. Effects of the reduced pressure on the environmental parameters have been investigated.

The Columbus fire suppression procedure is based on a centralized CO2 distribution system which injects the CO2 stored in a tank into the volume where the fire has to be extinguished. The fire is detected in each volume by means of the so-called REP (Rack Essential Package), which contains a fan and the smoke sensor. In order to assess the Fire Detection and Suppression design concept and to identify possible critical areas, Alenia Spazio - with the support of Flowsolve UK, and on behalf of EUROCOLUMBUS - has performed an analysis using a Computational Fluido-Dynamic (CFD) tool. The rack containing the water pump assembly and other electronic equipment has been chosen for the study. As far as the Fire Detection is concerned, the simulation intends to predict the flow field established in the rack by the ventilation system and the transport of smoke by this velocity field from a supposed point source.

Space hardware design, as well as that for hardware destined to work in 1-g environment, needs to be submitted to a complete design verification process before final utilisation in nominal conditions. As space hardware ground verification is difficult and expensive, a design verification philosophy has been developed in order to reach, as far as possible, the highest degree of space hardware reliability and usability and hence to increase crew productivity via a perfect integration of man and machines. This activity is mainly based on a complete hardware testing process (first on ground, then in microgravity simulated environment and, at the end, during a short duration space mission) and on a correct test procedure preparation in order to avoid inconveniences during test execution. Opportunity for an application of the design verification philosophy has been given by Columbus Precursor Flights and the related MIRIAM '95 programme.

The ITALSAT telecommunication system is based on the operation of two geostationary satellites: the first (pre-operative) launched in January '91 the second (operative) to be launched in '96. The thermal design of the satellites was extensively verified by analysis and test including a Solar Simulation thermal balance on the structural-thermal model and thermal vacuum - thermal balance on flight models. Additionally, on-orbit temperature data from the protoflight model is available for equinox and solstices 24 hr. transients. The results have been statistically processed and compared with test data and correlation analysis in order to provide a reliable background for thermal control design and verification of future similar telecommunication satellites.

The Mini Pressurised Logistic Module (MPLM) includes an Environmental Control and Life Support System (ECLSS), whose general purpose is to guarantee a comfortable environment for the Crew. In particular, among the functions of the ECLSS, there is the provision of a correct ventilation in the habitable area of the Module and an air flow adequate to support fire detection in powered zones. These tasks are carried out by an air ventilation system mainly composed of a fan, eight cabin diffusers and a ducting system. In addition, the ECLSS furnishes, through a dedicated distribution system, the capability to suppress fire by release of the Carbon Dioxide contained in a portable fire extinguisher.

The Columbus Attached Pressurised Module (APM) is intended to support a shirt-sleeve environment for crew activities. Top level requirements therefore define a cabin air temperature and humidity range (the so-called “Comfort Box”), extreme air velocities for ventilation in the centra aisle, maximum mean radiant temperature of the cabin walls. Air temperature selectability has to be ensured with adequate accuracy across the whole range. The APM environmental control system, in particular the Temperature and Humidity Control (THC) system, is designed and verified against these parameters. Cabin thermal conditions can be evaluated by the APM Integrated Overall Thermal Mathematical Model (IOTMM), representing the general thermal behaviour of the APM, including the THC system. Heat loads due to APM subsystem equipment and payloads, solar flux and the crew itself have been considered in the analyses.

Under the guidelines established by the European Space Agency (ESA), a specific effort was devoted to define the preliminary design concepts for a Crew Transport Vehicle (CTV) compatible with the Ariane 5 launcher. The mission objectives of this vehicle include the possibility of transporting 4 people (and a limited amount of pressurized payload) to the International Space Station Alpha (ISSA), and returning them to Earth safely. Different options were identified at system level, however a modular vehicle was commonly adopted: a Crew Module (CM) designed to withstand the typical phases of the atmospheric re-entry and provide an adequate environment for the crew during all the mission a Resource Module (RM) envisaged to provide the propulsion provisions for orbital transfer and deorbiting; in addition it carries all the necessary resources to support the mission from lift-off until separation from the CM.