Sentinel satellite launched to picture Planet Earth

[nitpicker]

http://www.bbc.com/news/science-environment-39183353

Sentinel satellite launched to picture Planet Earth

By Jonathan Amos
BBC Science Correspondent

8 hours ago

From the section Science & Environment

One of the key spacecraft in Europe's new multi-billion-euro Earth observation programme has launched from French Guiana. Sentinel-2B carries a large camera to image all land surfaces and coastal waters in visible and infrared light. It joins an identical spacecraft, Sentinel-2A, already in orbit. The duo will be flown on the same path but 180 degrees apart so that they can provide a complete map of Earth - clouds permitting - every five days.

The Sentinels constitute the space segment of the European Union's Copernicus environmental monitoring programme. A suite of sensors is being lofted over the next few years to gather critical information on the state of the planet and to acquire the data needed to inform and enforce EU policies. Applications range from urban planning and air-quality monitoring to tracking deforestation and glacier retreat.

Sentinels 2A and 2B are, in many senses, the centrepiece of this effort because their free and open picture resource will almost certainly find the widest use. "To say they are the 'heartbeat' is a good way to describe them because they take the images that are most easily understandable," Josef Aschbacher, the director of Earth observation at the European Space Agency (Esa), told BBC News.

The lift-off aboard a Vega rocket occurred on cue at 22:49 local time, Monday (01:49 GMT, 02:49 CET, Tuesday). Ejection of the satellite happened about an hour later, close to 775km above the Earth.
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