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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 aim of this paper is to present the Hermes Thermal Control Concept which constitutes the reference baseline for the phase 2 of the Hermes program. The technical solutions based on active and passive means, are dictated by a variety of requirements including temperature and heat flux limits, mass & power minimization, availability of space for accommodation of TCS devices. Furthermore thecomplex mission profile (including atmospheric flight and several modes of operation o002d;orbit) and the configuration of the space-vehicle, require the adoption of a particularly flexible thermal control. The ATCS (Active Thermal Control Section) is based on a dual loop concept, using both water and Freon R114 cooling loops for heat collection from the various sources, heat transportation and heat rejection through dedicated devices.

The requirements related to the thermal control of HERMES space-plane suggest the utilization of technical solutions based on active and passive techniques. The configuration of the space-vehicle with pressurized and unpressurized compartments presents a variety of different problems, which generally require dedicated solutions. The complex mission profile include atmospheric and orbital conditions, with several phases and modes of operation (free-flying and docked). The extremely wide range of environmental conditions, together with the timeline of internal power dissipations requires the adoption of a particularly flexible thermal control. The ATCS (Active Thermal Control Section) mainly relies on the capability of water and Freon 114 fluid cooling loops. They collect waste heat from the sources located inside the compartments and transport this power to the available rejection devices.