MELFI: Preserving biological samples in orbit
Air Liquide has already helped put astronauts in orbit, on board the International Space Station, by supplying NASA with the MELFI, a turbo engine that cools its laboratory freezer for preserving biological samples at -80°C. Our experience suggested that turbo-Brayton technology would be suitable. Our experts took great care to avoid mechanical wear and tear: the compressor wheel and the centrifugal turbines are mounted on a tungsten carbide shaft in suspension on a nitrogen film. This was an excellent precaution to have taken when you bear in mind that the MELFI, which was initially due to have an operating life of two years, is still working perfectly a decade later and should last until at least 2020: hundreds of thousands of hours later!
This success was the very first experiment with a turbo-Brayton engine in space. Today, Air Liquide is building a turbo engine capable of supplying 400 times more cooling power. A new challenge!