After the complete scientific documentation of the CERN Large Hadron Collider, JINST (Journal of Instrumentation) has now published 21 technical reports concerning the Planck Low Frequency Instrument on-board ESA's Planck satellite. They are open access and free for everyone to read.

"The technical papers presented here reflect the work carried out by the LFI Instrument Team and Data Processing Center over a period spanning more than 15 years prior to launch", says Marco Bersanelli, Planck/LFI Instrument Scientist. "The papers provide a detailed description of the design and ground-testing of the LFI critical sub-systems, including the main radiometer units, the optical components and the radiometer electronics. Because LFI is operated at cryogenic temperature, the instrument thermal design and its cryo testing represented a special challenge. Details of the noise properties of the instrument, as measured in the on-ground calibration campaign, are also reported, and finally, detailed descriptions are provided of the data analysis systems developed to support the instrument calibration".