The Sentinel-1B GO/NOGO roll call in the Main Control Room at ESOC, ESA's European Space Operations Centre, Darmstadt, Germany. The roll call was conducted by Flight Director Pier Paolo Emanuelli at 21:42 CEST, just 80 minutes before lift off at 23:02 CEST (21:02 UTC), 25 April 2016. Image credit: ESA
{{NOTE:: The roll-call from the previous day's launch attempt, on 24 April, which was subsequently scrubbed, is available here: https://soundcloud.com/esaops/sentinel1b_go_nogo_rollcall}}
Sentinel-1B will join the identical Sentinel-1A, which has been in orbit since April 2014, to form a twin-satellite constellation, orbiting 180° apart.
The Sentinel-1 mission will image the entire Earth every six days using radar, providing data that support vital services such as monitoring Arctic sea ice, surveillance of the marine environment and mapping for forest, water and soil management. More information via www.esa.int/sentinel1
