![Image - Press Release - 20171120 - Sentinel-3b Image - Press Release - 20171120 - Sentinel-3b](https://www-cdn.eumetsat.int/files/styles/16_9_large/s3/2020-04/img_prs_171120_s3b.jpg?h=199d8c1f&itok=VC825ViK)
EUMETSAT ground segment is ready for the launch of Copernicus Sentinel-3B
![Image - Press Release - 20171120 - Sentinel-3b Image - Press Release - 20171120 - Sentinel-3b](https://www-cdn.eumetsat.int/files/styles/16_9_large/s3/2020-04/img_prs_171120_s3b.jpg?h=199d8c1f&itok=VC825ViK)
![Image - Press Release - 20171120 - Sentinel-3b Image - Press Release - 20171120 - Sentinel-3b](https://www-cdn.eumetsat.int/files/styles/3_4_large/s3/2020-04/img_prs_171120_s3b.jpg?h=199d8c1f&itok=terXGsJf)
EUMETSAT has confirmed the readiness of its teams and the new version of its ground segment to support the launch and commissioning of the Copernicus Sentinel-3B satellite in a two-satellite configuration with Sentinel-3A.
05 November 2024
05 December 2017
The new version of the ground segment includes enhancements and upgrades necessary to exploit a dual Sentinel-3 system. Its acceptance follows a comprehensive campaign of verification and validation tests.
During the commissioning of Sentinel-3B, the two Sentinel-3 satellites will fly in close formation, 30 second apart. In this phase, ESA will manage Sentinel-3B flight operations, and EUMETSAT will be progressively ramping up its flight control activity to prepare the hand-over, while continuing to perform flight operations of Sentinel-3A.
![Copernicus control centre at EUMETSAT headquarters](https://www-cdn.eumetsat.int/files/2020-04/img_prs_171120_s3b.jpg)
The close formation flight will allow to compare thoroughly the measurements from all instruments aboard Sentinel-3A and –B, ensuring the best consistency between the products from the two satellites.
The completion of commissioning will lead to a handover of the Sentinel-3B satellite from ESA to EUMETSAT once the latter has been moved to it final orbital position, at a 140º phasing from Sentinel-3A, to form the full Sentinel-3 constellation. The 140° phasing was chosen to optimise global coverage and ensure optimised sampling of ocean currents by the combined altimeters on board Sentinel-3A and -3B.
Thus the Sentinel-3 constellation will also realise the best possible synergy with the cooperative Jason-3 high precision ocean altimeter mission, another Copernicus marine and climate mission exploited by EUMETSAT on behalf of the European Union.
Under the Copernicus data policy, all Sentinel-3 marine data and products are available on a full, free and open basis to all users through EUMETSAT’s Near Real Time dissemination channels EUMETCast, the Copernicus Online Data Access and EUMETview.