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Herschel and Planck satellites have recently undergone the thermal vacuum and thermal balance (TVTB) test which was performed in the ESA-ESTEC Large Space Simulator for Herschel and in Centre Spatial de Liège (CSL) for Planck. One of the specific targets of the Herschel test was the verification of the thermal stability of two HIFI units (required to be better than 3.10−4 °C/s) and of the Star Tracker mounting plate (required to be better than 2.5.10−3 °C/s), with particular attention on the performance of the relevant feedback control loops. Control system design and model predictions are presented and compared against the test results. Further discussion on the requirement verification is provided.

The Automated Transfer Vehicle (ATV) is one of the major European contributions to the International Space Station Alpha (ISSA). The ATV will be launched with ARIANE 5 and will be used for servicing of ISSA with pressurized and unpressurized cargo as well as for ISSA refuelling and reboost. The ATV consists of a Core Module and a Cargo Module. The Core Module includes all major subsystems including the propellant tanks required for the automated flight to ISSA. Eight 400 N thrusters are accommodated on the bottom platform for orbit transfer and reboost of ISSA. Twenty 200 N thrusters, accommodated on the cylindrical shell of the core module, are provided for attitude control. The thermal control of the ATV consists of a passive subsystem supported by an electrical heater system. The waste heat of most of the avionics equipment is collected and transferred via conduction through the box baseplate to the avionics platform and further on to the cylindrical shell.

ESA has planned two important missions for performing astronomical investigations in the infrared and sub-millimetre wavelength range: Herschel satellite has an observatory type mission and is the fourth cornerstone mission (CS4) of the “Horizon 2000” programme. It will carry three instruments (HIFI, SPIRE, and PACS) for high and medium resolution spectroscopy, imaging and photometry over the sub-millimetre and far-infrared range. A 3.5 m telescope will focus the incoming radiation on the Focal Plane Units of these instruments. Planck satellite has a survey type mission and is the third Medium mission (M3) of the “Horizon 2000” programme. It will provide a definitive high-angular resolution map of the cosmic microwave background anisotropies over at least 95% of the sky and over a wide frequency range. A 1.5 m telescope will focus the incoming radiation on the focal plane shared by the two instruments (LFI and HFI).