Active Thermal Control Subsystem of the SPACELAB D2 Payload “Critical Point Facility”

New components have been developed for an active thermal control system, to meet the extreme thermal requirements of the SPACELAB fluid science “Critical Point Facility”.

A water cold plate with a double spiral fluid channel acts as a variable conductance heat sink for the high precision thermostat. This channel geometry achieves high heat flux densities on its planar isothermal contact surface.

A thermostat unit consisting of two thermo-electrical Peltier element heat pumps and one electrical heater regulates the upstream temperature inside an air cooled electronic box. Both of these elements are pulse-width operated, to compensate the environmental temperature fluctuations.