Europe launches earth-monitoring satellite

Credit: ESA–Stephane Corvaja, 2017

Europe has launched a fifth Sentinel Earth observation satellite that will monitor the earth by providing images of land, oceans and waterways as part of its multi-billion-euro Copernicus program.

The Sentinel 2B will play a leading role as part of a system of satellites in the world's most ambitious Earth observation programme.

The satellite was launched on a Vega rocket from the European Space Agency (Esa) base at Kourou, French Guiana at 8:49 p.m. EST (0149 GMT on Tuesday).

The £95 million spacecraft will join its twin Sentinel-2A which has been in orbit since 2015.

Its task will be to take high-resolution, colour and infrared images for a wide number of environmental projects including crop forecasting and monitoring natural disasters.

The Vega rocket carrying Sentinel-2B in its mobile gantry at Europe's Spaceport in French Guiana. Credit: ESA–Stephane Corvaja, 2017

Both satellites will orbit the planet at a height of 488 miles, on opposite sides of the Earth.

Every five days the spacecrafts will cover all of the earth's surfaces providing more up-to-date images and information than ever before.

This will enable it to study the health of crops and forests, track the growth of cities, and detect the effects of changing land use and global warming on the Earth's vegetation.

Sentinel 2B will also be used to monitor natural disasters caused by floods, earthquakes and volcanic eruptions, and support humanitarian relief efforts.

Over the next seven years Copernicus, which includes several Sentinel missions, will cost an estimated £3.7 billion.

The programme is expected to return at least 10 times that figure to the EU economy, even though its treasure trove of data is being offered completely free to companies, governments and institutions around the world.

Sentinel 2 complements but outperforms the US Landsat series of satellites that has been the prime provider of Earth observation data since 1972.

Landsat 8, the latest satellite, can "see" only eight colours and has a resolution of 30 metres compared with Sentinel 2's ten.

Working on its own, Landsat offers a global view of the world every 16 days instead of five.

The Sentinel 2B launch pad showing the housing encasing the Vega rocket. Credit: John von Radowitz/PA Wire

Josef Aschbacher, director of Earth observation programmes at Esa, said:"For the first time we (Europe) are leading the global monitoring aspect of space. There's nothing comparable in America, in Japan, in Russia, in India.

Between them the satellites will generate 1.6 terabytes of compressed raw image data daily.

The total amount of data available from Copernicus is astounding. Even before the launch of Sentinel 2B, around 21 petabytes of data had been downloaded from the system. A petabyte is equal to a thousand million million bytes.

"This is a high number, maybe difficult to imagine," said Mr Aschbacher.He added that each day Copernicus was producing more data than all the photos and movies uploaded on Facebook.

Other Sentinel missions, some yet to be launched, will collect data on the oceans, atmosphere and climate.