The CALIPSO mission was interrupted on 28 January, 2016 because of a GPS receiver issue. The payload went back to a nominal data acquisition state on 14 March 2016. Expedited data processing and standard processing resumed on that day along with data distribution at ICARE and NASA/LaRC. Unfortunately, data loss between 28 January and 14 March 2016 is unrecoverable.
More information on the incident can be found on the CNES-CALIPSO website:
in French: https://calipso.cnes.fr/fr/mission-calipso-suspendue-du-28-janvier-au-14-mars-2016
in English : https://calipso.cnes.fr/en/calipso-mission-suspended-28-january-14-march-2016