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NIRSpec is a near-infra-red spectrometer and one of the four instruments onboard the James Webb Space Telescope (JWST). The JWST observatory will be placed at the second Lagrange point (L2). The instrument will be operated at about 30 Kelvin. Temperature stability and controlled heat rejection to dedicated JWST radiators are important issues of the NIRSpec thermal design. Besides thermal insulation, the NIRSpec Optical Assembly Cover also has to provide light tightness and stray light suppression to prevent unwanted light entering the instrument. Air tightness is needed to allow a controlled purge gas flow for contamination prevention while allowing proper air venting during launch. Because of mass constraints a cover employing two-foil Kapton blankets supported by aluminum posts and a wire tent was chosen. Failure tolerance and cleanliness are other important design drivers. This paper describes the design solutions established to fulfil the contrary requirements

CryoSat is the first satellite of ESA's Living Planet Programme realised in the framework of the Earth Explorer Opportunity Missions. CryoSat is a radar altimeter mission dedicated to determine trends in the ice masses of the Earth. The overall spacecraft configuration was driven by the budget constraints applicable for the opportunity mission, the high inclination orbit with drifting orbit plane and the stringent stability requirements for the radar altimeter antennas. Innovative thermal design solutions were needed for the following items: The instrument antennas have to comply with very stringent pointing stability requirements. The star trackers need to be mounted at a thermally adverse position and still have to be maintained on low temperature levels.

The objective of the Laser Interferometer Space Antenna (LISA) mission is the detection of low-frequency gravitational waves. The fluctuation of the distance of test masses inside 3 spacecraft’s which are located 5·106km apart is measured with an accuracy of 10−12m to achieve this. This requires very stringent temperature stability. Variations of solar constant, dissipation and the response to switching/mode changes cause temperature fluctuations that have to be suppressed. The spacecraft thermal design relies on a solar array as a sun shield with good thermal de-coupling between the solar cells and the structure and rejection of heat from the electronics directly to space. MLI is avoided because of its potentially unstable insulation properties. Transient analyses were performed with a temperature accuracy of 10−8 K. It was found that the fluctuations caused by the solar constant are sufficiently damped.

The redesign of the international Space Station Freedom (SSF) and funding constraints in the ESA member states caused a redirection of the development effort for the Attached Pressurised Module (APM). For the ECLSS the most important changes are the reduction in length of the module in order to make it compatible with the ARIANE V capabilities and the more severe cost constraints. As a result new concepts for the cabin loop were investigated leading to a decrease in cabin loop power consumption, mass and volume and a reduced development effort due to a lower number of items. In the previous concept a module internal loop with a flow rate of 864m3/hr and an Intermodule Ventilation (IMV) flow rate for air revitalisation to the station with 240m3/hr were installed. The revised boundary conditions with a reduced overall massflow rate of 540m3/hr allows the combination of the cabin loop and the IMV with limited impact on the total power consumption.

The COLUMBUS APM employs CO2 stored in centralized tank or, as backup, in portable fire extinguishers (PFEX) for the suppression of eventual fire events. The conditions of the 2-phase flow of the CO2 in the tank and in the ducting system are an important parameter for the layout of the system. In this paper the analytical and experimental work performed to determine these flow conditions and the results for the baseline fire suppression system shall be given.

The pressurized modules use water and air coolant circuits to remove the dissipated heat from the sources and to transport it to the heat sink. The advantage of the water loops is to provide a high heat removal capability at low power consumption well suited for high specific heat loads i.e. assemblies with high dissipation and small volume. Air coolant circuits offer a higher flexibility to account for different shapes of the equipments and for changes in the configuration of the loop. Thus they are better suited for assemblies with lower dissipation and do not impose as much design restrictions on assemblies as water loops. But they have a higher specific power demand compared to water loops. In the Columbus pressurized modules avionics air loops and cabin air loops are installed. Both of them belong to the Environmental and Life Support Subsystem (ECLSS).

Potential fires in the COLUMBUS Attached Pressurized Module (APM) shall be extinguished by reducing the O2 concentration in the atmosphere below 15 %. For this purpose a CO2-distribution system is foreseen. It injects CO2 stored in a tank into the volume where fire is to be extinguished. Due to its dimensions the most critical of these volumes is the subfloor with the stand-off areas. To investigate the fire suppression process a detailed three dimensional computational fluid dynamic analysis (CFD-analysis) was performed. The transient CO2-distribution mechanisms, forced convection and diffusion, were analyzed to examine the feasibility of the foreseen system and to optimize it. In this paper the governing physical processes and their implementation in the mathematical model of the problem are described. The very complex inlet conditions - speed of sound, tiny nozzles - are examined in detail to investigate a proper method for implementation in the mathematical model.