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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.

The Total Off-gassing test purpose is to determine the identity and quantity of trace gas contaminants offgassed in areas of spacecraft where the crew will breathe the atmosphere. Two different air sampling methods were adopted in parallel during the off-gassing tests on the Multi-Purpose Logistics Modules (MPLM) by Alenia Spazio. The first method, based on NASA (National Aeronautics and Space Administration) requirements, foresees storage of collected air samples into stainless steel pressure cylinders. The second method proposed by ESA (European Space Agency), uses trace contaminants adsorption on Carbopack™ filled ceramic tubes. Sample lines route the samples collected inside the MPLM cabin, to the respective external collection points. Successively, the stored samples are chemically analyzed by Gas Chromatography / Mass Spectrometry (GC/MS) techniques and the module offgassing rates are calculated.

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.

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.

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 Mini Pressurised Logistics Module (MPLM), a cooperative project between NASA and ASI that will be designed, developed, produced, integrated and delivered by Alenia, is a pressurised volume devoted to the resupply and return of Space Station (SS)containerized cargo requiringapressurised environment, via the National Space Transportation System (NSTS). As a servicer for the SS, the MPLM will have to accomplish several trips between Earth and SS in support of logistic needs. Since the active payloads launched with MPLM (freezers and refrigerators) require resources during the transportation phase inside the NSTS, the MPLM has the peculiar capacity to exchange power, data and fluids with the Orbiter before docking to SS. Once docked to SS, the MPLM will be required to provide its full performance, making use of the resources available from the SS Node; nevertheless, in this phase some of the MPLM functions are demanded from the SS.

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.