Europe's environmental monitoring program, Copernicus, has a new eye in the sky.

Another Sentinel satellite launched Monday atop a Soyuz rocket is the latest addition to a suite of satellites recording data and images about various Earth processes.

The new addition, Sentinel-1B, joins its twin, Sentinel-1A, carrying radar technologies that can image the surface of the planet day or night, sun or rain. Orbiting 180 degrees apart, the two satellites together will complete a full map of the Earth's surface every six days.

"This is the fourth satellite that we’ve launched for Copernicus in just two years and this launch is certainly a special moment because it completes the Sentinel-1 constellation," Volker Liebig, the European Space Agency's director of Earth Observation Programmes, said in an ESA press release.

"The launch of Sentinel-1B marks another important milestone as this is the first constellation we have realised for Copernicus," said ESA’s Director General Jan Woerner.

Sentinel-1A was launched in April 2014. Since then, the satellite has helped experts monitor the melting of Earth's ice caps and ice sheets, warn of icebergs, and map geological processes, like shifts from earthquakes and volcanoes. The satellite has also been used to monitor fisheries in the Mediterranean.

"We have seen some marvelous results from Sentinel-1A. Only two weeks ago, for example, it captured images of large icebergs breaking away from Antarctica’s Nansen ice shelf," Dr. Liebig said. "Given that Antarctica is heading into winter now and daylight hours are getting shorter, radar images are vital to see what changes are taking place."

Sentinel-1B wasn't the only passenger on the Soyuz rocket that blasted into space Monday. Three student-designed CubeSats and a Microscope satellite, a French space agency probe, hitched a ride too.

Get the Monitor Stories you care about delivered to your inbox. By signing up, you agree to our Privacy Policy

The CubeSats, itty-bitty satellites that are just about 4x4x4.3 inches, are part of ESA's Education Office's Fly Your Satellite! program. They were designed and programmed by three university teams from the University of Liege, Belgium, the Polytechnic of Turin, Italy, and Aalborg University, Denmark.

"The programme is helping to educate the next generation of scientists and engineers by transferring ESA knowhow in designing, building, testing, launching and operating satellites," said Piero Galeone, ESA’s Head of the Tertiary Education Unit.