Climate Change News

Rapidly Activated Satellite Completes A European Constellation

Sentinel-1B will move to a new orbit on the other side of our planet from its sister spacecraft Sentinel-1A.


A European Earth-observing satellite captured a crisp image of northern Norway Thursday in record time—just 2 hours after the spacecraft’s radar was activated, the European Space Agency (ESA) announced.

The agency, which launched the Sentinel 1-B satellite on Monday, reported that the new spacecraft had acquired its first images after successfully deploying a 12-meter-long radar antenna as well as two 10-meter-long solar arrays. Sentinel-1B will observe land and ocean.

The agency said that upcoming maneuvering by Sentinel-1B will place it in a final orbit on the other side of Earth from its sister satellite Sentinel-1A. That shift will complete a planned constellation that also includes previously launched Sentinel-2—primarily for observing land—and Sentinel-3, mainly for ocean observation.

“With another important milestone reached, we now have the fourth satellite in orbit and the Sentinel constellation as we envisaged it becomes a reality,” said Philippe Brunet of the European Commission.

Sentinel-1B and Sentinel-1A, which launched in 2014, can both image Earth’s surface during day or night, through clouds and rain, according to ESA. Because their radars can peer through clouds, they provide “a very useful complement to Landsat,” said Jeffrey G. Masek, chief of the Biospheric Sciences Laboratory at NASA’s Goddard Space Flight Center in Greenbelt, Md. Clouds interfere with Landsat scrutiny, he said.

Masek praised “the free and open data distribution policies adopted by the Sentinel program.” Those give U.S. researchers access to the constellation’s data and support international collaboration, he added.

Sentinel-1B will undergo tests and calibrations in the coming months before being declared fully operational, according to ESA.

—Peter L. Weiss, Senior News Editor; email: [email protected]

Citation: Weiss, P. L. (2016), Rapidly activated satellite completes a European constellation, Eos, 97, doi:10.1029/2016EO051589. Published on 29 April 2016.

© 2016. The authors. CC BY-NC-ND 3.0