The study of the cold Universe allows us to go back to the origins of our solar system with the observation of star embryos and the origins of the Universe with the measurement of the polarization of the Cosmic Microwave Background. The astronomical instruments in the sub-millimetre and millimetre domains require the use of superconducting detectors cooled down to 100mK. This makes these experiments particularly complex to implement, especially at the system level. A simplification of cryogenic systems would be a major asset for future instruments.