Planck Mission

140 Millons Euros HFI Is The Main Instrument Of Planck. It Has Been Assembled In 2008 At The Thales Alenia Space Plant in Cannes, France. One of the most incredible temperature detector in the world. Separated from its 1.5m-diameter telescope, the High Frequency Instrument (HFI) is one of the two instruments of this observatory. Planck will provide a map of the sky with unprecedented precision, showing temperature and polarisation fluctuations in the cosmic microwave background radiation. The HFI instrument, developed under French prime contractorship, will actually be able to detect temperature fluctuations of close to one millionth of a degree around the temperature of the cosmic microwave background radiation of 2.7K, using sensors cooled to just 0.1 Kelvin above absolute zero (or minus 273 degrees C). (Photo by Frederic CASTEL/Gamma-Rapho via Getty Images)