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This paper describes the thermal design and analysis of RADARSAT-2, a commercial Synthetic Aperture Radar (SAR) satellite for earth observation. The particular thermal design challenges faced by RADARSAT-2 are the continually varying thermal environment imposed by its dawn-dusk, sun-synchronous orbit and the wide range of operational capabilities of the SAR payload. The SAR antenna is a 15m active array design that incorporates 512 transmit/receive (T/R) modules distributed throughout the antenna panels. The thermal environment for these high-dissipation units must be maintained throughout the various mission configurations. The Bus and the Extendable Support Structure (ESS) which deploys and supports the SAR antenna must provide a thermoelastically stable platform from which to mount the SAR antenna as well as the attitude sensors.

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.

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.

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 Attached Pressurised Module (APM) is the European element of the NASA Space Station Freedom (SSF). The environmental control of the APM is obtained through the combined effort of the Water Loops of the Thermal Control Subsystem (TCS) and the Cabin and Avionics Loops of the Environmental Control and Life Support Subsystem (ECLSS). Although the specific functions of ECLSS and TCS are separately verified at subsystem (S/S) level, their overall qualification is completed only after having carried out the functional and performance verification of the integrated Environmental Control System (ECS) inside the APM. To this purpose too, an APM Engineering Model (EM) development has been included in the programme. The Engineering Model is the element prototype, fully representative of the APM Flight Model (FM) but for the quality of the EEE components, as they are requested to be MIL-grade but not Hi-Rel.

At present, limited tools are available to model atmosphere control and supply systems simply, in order to allow quick design assessments based on analytical performances. In this context, the utilization of PC based ESACAP adapted as an Atmosphere Control and Supply (ACS) simulation tool is described. The analyses results shown in this paper refer to the activities of MPLM baseline re-definition carried out in accordance with the Space Station re-configuration. As a consequence, in several cases the described analyses reflect conservative assumptions and have been performed in a parametric way so as to take the uncertainties into account.

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.

A Human Factors Engineering (HFE) analysis has been involved in the design process of the Mini Pressurized Logistics Module (MPLM) for the International Space Station (ISS) since the beginning, as an integrated part of the design support activities. The support of HFE in the configuration process has been directed towards the optimization of the MPLM design through the analysis and evaluation of all the interfaces occurring in the module - nominal and non-nominal - between the crew, the system and the subsystem equipment. In order to identify and analyze all the crew interfaces occurring inside the module, a systematic approach, involving different disciplines, is necessary. The integration of three different tools such as computer simulation, task analysis and mock-up test activities has been employed as an organic unit, in order to establish a comprehensive collection of useful data.

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 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.

In the overall planning of a manned mission to Mars, all the issues related to human involvement are critical. To a certain extent, they dictate the most severe constraints on the mission scenario and spacecraft architecture. Despite this unanimously recognized importance, limited efforts have been devoted up to now to dedicated research activities on human-related aspects, partially neglected w.r.t. more technical areas like orbital dynamics, propulsion, power generation, etc. This paper summarizes the major results of a survey on the human factors of long duration missions performed by Alenia Spazio in the frame of an ESA study, MARSEMSI, whose aim was to identify possible scenarios and related infrastructure requirements for a manned mission to Mars.

Thermo-hydraulic mathematical models of manned modules of the International Space Station [ISS] require to simulate also air-vapour flow in Environmental Control Systems [ECS] circuits. Although this can be obtained with available S/W, a complementary solution was developed, in order to overcome some S/W limitations and to ease exchange of models. It consists of a set of FORTRAN subroutines, that can be added to ESATAN/FHTS and SINDA/FLUINT thermo-hydraulic models for dry air, and simulate the effect of vapour in the airflow.