Sentinel-1B

Sentinel-1B
Name	Sentinel-1B
Mission	Earth observation
Operator	European Space Agency
Mission type	Synthetic Aperture Radar imaging
Launched	2016-04-25
Launch vehicle	Soyuz-2
Launch site	Guiana Space Centre
Manufacturer	Airbus Defence and Space
Instruments	C-band SAR
Orbit	Sun-synchronous orbit

Sentinel-1B

Sentinel-1B was a European Union Earth observation satellite developed under the Copernicus Programme and operated by the European Space Agency. It formed part of a twin constellation with a sister satellite to provide C-band synthetic aperture radar continuity for applications including European Union Territorial policies, maritime surveillance tied to International Maritime Organization frameworks, and environmental monitoring supporting United Nations Framework Convention on Climate Change initiatives. Designed and built by Airbus Defence and Space, it carried a C-band radar instrument to deliver all-weather, day-and-night imagery for civil and security use.

Overview

Sentinel-1B was one of a pair of Sentinel-1 satellites commissioned by the European Commission and implemented by the European Space Agency under the Copernicus Programme to ensure continuity with historical radar missions such as ERS-1, ERS-2, and Envisat. The satellite contributed to operational services managed by the Copernicus Services including Copernicus Emergency Management Service, Copernicus Marine Environment Monitoring Service, and Copernicus Land Monitoring Service. Its mission supported interoperability with international initiatives like the Group on Earth Observations and data sharing with partners including NASA and CSA.

Mission and Objectives

The primary objective was to provide routine, systematic C-band synthetic aperture radar (SAR) imagery for applications spanning European Environment Agency reporting, Intergovernmental Panel on Climate Change assessments, and North Atlantic Treaty Organization situational awareness requests. Operational goals included wide-area surveillance for Fisheries and Oceans Canada-style maritime monitoring, tsunami and flood mapping akin to United Nations Office for Disaster Risk Reduction priorities, and ice monitoring in coordination with polar programs such as International Arctic Science Committee. The mission aimed to ensure near-real-time delivery to services like the Copernicus Emergency Management Service and to support research communities associated with institutions like Max Planck Society and Imperial College London.

Spacecraft and Instruments

Built by Airbus Defence and Space with payload contributions coordinated by ESA, the platform hosted a C-band SAR instrument derived from heritage designs used on ENVISAT and other European SAR missions. The SAR instrument supported multiple acquisition modes including Interferometric Wide Swath and Extra-Wide Swath to enable interferometry and maritime surveillance for organizations such as European Maritime Safety Agency. Onboard systems included attitude control and thermal subsystems influenced by designs used on PROBA missions, and data handling units compatible with ground processing chains developed by the European Organisation for the Exploitation of Meteorological Satellites and national agencies like CNES and DLR.

Launch and Orbital Details

Sentinel-1B was launched on 25 April 2016 aboard a Soyuz-2 rocket from the Guiana Space Centre in French Guiana, in a campaign coordinated by the European Space Agency and Arianespace. It was injected into a sun-synchronous, near-polar orbit phased to provide constellation coverage complementary to its sister satellite, ensuring 6-day to sub-daily revisit capabilities over mid-latitude areas and improved repeat-pass geometry for interferometric applications pursued by institutions such as Delft University of Technology and Politecnico di Milano. The orbital configuration supported systematic acquisitions for global mapping products distributed through ESA nodes and national mirror sites like UK Space Agency archives.

Operations and Data Products

Operations were conducted from ESA mission control elements with mission planning and payload operations coordinated with the Copernicus Services and national agencies including CNES and DLR. Data products included Level-0 raw SAR, Level-1 Single Look Complex and Ground Range Detected products, and Level-2 interferometric and geophysical products used by users such as the European Environment Agency and International Maritime Organization. The Sentinel-1 processing chain integrated tools from the European Space Operations Centre and scientific toolkits used by research groups at University of Oxford and TU Delft. Open data policies aligned with the Copernicus Data Policy enabled widespread use by academia, industry, and humanitarian organizations like Red Cross.

Incidents and Anomalies

During its operational life, Sentinel-1B experienced anomalies requiring intervention by ESA operations teams and coordination with manufacturers like Airbus Defence and Space. In [an incident] the satellite suffered an unexpected platform failure that led to cessation of regular data deliveries and triggered contingency planning involving the European Commission and partner agencies. Recovery attempts included software updates and cross-calibration activities with the sister satellite and international missions such as Radarsat-2 and TerraSAR-X; however, prolonged loss of functionality led to accelerated reliance on the remaining constellation and international collaborations for continuity.

Legacy and Impact

Sentinel-1B significantly advanced operational radar remote sensing by providing freely available, high-quality C-band SAR data that underpinned services across climate, environment, disaster response, and security sectors. Its datasets supported high-impact studies by research centers like Potsdam Institute for Climate Impact Research and NASA Jet Propulsion Laboratory, contributed to policy assessments in the European Environment Agency, and fostered commercial value chains across companies influenced by Airbus and start-ups in the European space sector. The mission strengthened international cooperation frameworks involving European Space Agency, European Commission, NASA, and other space agencies, leaving a legacy of open-data practice and improved Earth observation capabilities.

Category:European Space Agency satellites Category:Copernicus Programme