A few hours ago, the Sentinel-2B satellite of the Copernicus / GMES program, blasted off from the Kourou base, French Guiana, on a Vega rocket. Shortly after, the spacecraft regularly separated from the rocket’s last stage and started sending signals. A few hours later it started deploying its solar panels.
The program originally called Global Monitoring for Environment and Security (GMES) and later Copernicus is intended to create an autonomous system of territorial control through a constellation of satellites that have different functions. The first Sentinel satellite was launched in April 2014 to open a new era in Earth observations from space.
The Sentinel-2B satellite is equipped with a multispectral camera that captures images in 13 spectral bands ranging from visible light to short-wave infrareds. It has a 290 kilometers (180 miles) swath to provide a control of the territory at a very advanced level.
This work has been accomplished so far by the Sentinel-2A satellite, launched in June 2015. Its twin Sentinel-2B will be placed in the same orbit and the two of them will be on opposite sides of the Earth. Apart from their specific work, they will be used together with other satellites of the Copernicus program concerning issues such as climate change, the management of emergencies and environmental safety. The data they’ll gather can also be used in combination with other satellites.
The acquisition of images of the territory by the two Sentinel-2 satellites aims in particular to monitor vegetation, soil and water, which also means crops. The Sentinel-2A satellite has already improved the mapping of the territory to more accurately assess the breakdown of the various areas, from the use of land to forests but also of geophysical changes. When the work will be carried out by the two satellites together, the global coverage will be accomplished in five days.
After the test period, the Sentinel-2A satellite will begin its mission, which has an expected life of 7 years. Its orbit, which has an altitude of 786 kilometers (488 miles), is sun-synchronous, which means that it alwasy flies over a certain area of the Earth at the same local time.
Initially, the Sentinel-2B satellite was put into orbit that is 11 kilometers (almost 7 miles) lower to avoid collisions with its twin. Only when it reaches the correct position it will be possible to begin the sequence of maneuvers to move it to its final orbit.
Here’s a video of the Sentinel-2B satellite launch.