Thermal Control Architecture of the Automated Transfer Vehicle

The Automated Transfer Vehicle (ATV) is a European Space Agency autonomous, expendable logistic transportation system for Low Earth Orbit. The ATV will be launched by Ariane 5 and its mission is to contribute to the logistic servicing of the International Space Station:

• via the delivery of a cargo (crew items, scientific experiments, spare parts..) as well as of fluids such as propellant, water and compressed air
• via the provision of an extra service consisting of retrieving the station wastes when departing (replacing the upcoming cargo) and getting rid of them through the final destructive atmospheric re-entry of the ATV itself
• via the contribution to the orbit control of ISS by providing a reboost and attitude control capability to the ISS.

The ATV consists of a Spacecraft and an Integrated Cargo Carrier. The Spacecraft includes all subsystems necessary for the automated flight to the ISS and for the reboost, including the propellant tanks and the thrusters. A Micro-meteroid and Debris Protection (MDPS) is covering most of the Vehicle. A portion of this MDPS on the Spacecraft is used as radiator by the ATV Thermal Control to reject to space the waste heat generated by the ATV avionics. The Cargo Carrier consists of a Pressurized Module which carries dry cargoes and an unpressurized module which carries water and compressed air in tanks as well as a refuelling system which includes fuel tanks, plumbing and the associated control electronics. A Russian Probe and Drogue docking system (Progress and Soyuz type) and the related control electronics are mounted on the Pressurized Module in order to allow the docking to the Space Station and the crew access to the module interior for cargo load/unload operations. This paper gives an overview of the chosen ATV passive thermal control concept requiring the adoptions of technical solutions compatible with the different environmental conditions, the flight attitudes, the various operating modes (the vehicle is fully active during the free-flying phases but it is in dormant mode when docked to ISS, with the most of the equipment switched off) and the limited available electrical power from the station.