20 K Continuous Cycle Sorption Coolers for the Planck Flight Mission Available to Purchase

Two sorption coolers using Hydrogen as the working fluid are currently being fabricated and assembled for flight delivery by the Jet Propulsion Laboratory (JPL). These systems have been designed to provide a total cooling capacity (per cooler) of 1 W at a cold end temperature less than 19 K with a temperature stability of 100–450 mK over a cooler cycle. Being vibration free, scalable and with the capability for the cold end to be remotely located from the warm spacecraft are the major advantages of this class of cryocoolers. This sorption cooler design has been validated by tests on components, subsystems and a fully integrated breadboard cooler (including electronics) at JPL where the two flight units are now being assembled for delivery to Europe in 2005. They will be used for the Planck Surveyor mission, which will perform high‐resolution measurements of the cosmic microwave background anisotropy. In this paper we present the level of maturity of the hydrogen sorption cooler technology at JPL by describing the design and how it has been validated at the subsystem and system levels. In addition, we will describe how such systems could be advantageously used for other space missions with similar needs and cooler attributes.