Cryogenic cooling and refrigeration
As an expert in cryogenic equipment, Air Liquide has achieved something that had never been done on a spacecraft! For the International Space Station, we designed the MELFI turbo-engine, which cools biological samples to – 80°C and has been operational for 10 years. This is quite an achievement when you bear in mind it was only intended to run for two years!
We fitted out Planck and Herschel, the most complex satellites ever produced in Europe. We developed and qualified a dilution refrigerator at 0.1 Kelvin for Planck, which later produced a map of the universe's cosmic background microwave radiation. We produced a huge helium tank to cool the powerful Herschel telescope. Since then, Herschel has produced results that explain how the stars were born. One of our biggest challenges with these satellites was the absolute necessity to avoid leaks, which required high-precision welding work.
Air Liquide is also developing an innovative pulse tube cooling technology. For satellites, where there is a limited amount of space for equipment, active cooling technology is the most appropriate.
Did you know? The Planck and Herschel telescope's detectors are cooled to a temperature close to absolute zero, allowing it to scan regions of space where temperatures don't exceed 3 Kelvin.