Planck space observatory cooling system at one degree Kelvin,artwork. This unmanned spacecraft,launched on 14 May 2009,is designed to study the Cosmic Microwave Background (CMB),the radiation left over from the Big Bang. To achieve this,the Planck instruments,the Low Frequency Instrument (LFI) and the High Frequency Instrument (HFI),operate at a few degrees above absolute zero. To achieve this,a series of cooling stages are required. The artwork shows the third and last cooling stage,bringing down the temperature of the HFI instruments to around 0.1 Kelvin |