Status And Evolution Of The Sentinel-1 Mission

The Copernicus Sentinel-1 mission ensures continuity of C-band SAR observations for Europe. The mission is characterized by large-scale and repetitive observations, systematic production and a free and open data policy. Sentinel-1 data are routinely used by Copernicus and many operational services, as well as in the scientific and commercial domain. Sentinel-1 is based on a constellation of two SAR satellites, Sentinel-1A and Sentinel-1B that have been launched from Kourou on a Soyuz rocket on 3rd April 2014 and 25th April 2016 respectively. At the time of finalising this paper (31 May 2022), the operations of Sentinel-1B have been interrupted due to an anomaly on the satellite power sub-system, that occurred on 23 December 2021. This is a major anomaly that will probably result in a permanent loss of the satellite. Detailed investigations are close to completion, and unfortunately, all attempts to bring back the faulty power unit to nominal operations have failed. The paper provides some details on the Sentinel-1B power anomaly and on the mitigation actions performed at mission level to compensate, to some extent, the lack of Sentinel-1B data.