And if you're wondering "So what?", Sentinel 1 is the first piece in a huge global monitoring project coming from the European Space Agency. The Copernicus global network of data collecting systems, from satellites to down on the ground, will be collecting terabytes of data on the environment. This has huge implications for monitoring Climate Change, resource planning, disaster response, environmental policy and more.
The Sentinel-1a spacecraft has been put in orbit on a mission to map the planet's surface using radar.
It will be followed by a fleet of other satellites - also called Sentinels - over the next five years.
Brussels is describing its Copernicus programme as the biggest ever effort to characterise our world.
Sentinel-1
Sentinel-1a will play an important role in responding to natural disasters
When the full satellite system is operational, it will be producing daily some eight terabytes of data to detail the state of Earth's land surface, its oceans and its atmosphere.
European nations have so far committed 7.5bn euros (£6.2bn; $10.3bn) to the project. But the vision for Copernicus is that it is unending - that every Sentinel satellite is replaced at the demise of its mission, ensuring there is continuity of information deep into this century.
"Once all the Sentinel satellites have been launched, the Copernicus programme will be the most efficient and fullest Earth-observation programme in the world," said European Commission President Jose Manuel Barroso.
"This investment will allow Europe to establish itself at the forefront of research and innovation in a cutting-edge sector - namely, space. Many skilled jobs have been created and many more are yet to come."
The potential of Copernicus is extremely rich. Given the amounts and type of data to be collected, it's likely that entirely unanticipated uses will also develop as researchers and others start going through it. Assuming Sentinel 1 checks out and gets to work on schedule, it should kick off what looks to be a really valuable asset for helping us better manage what we do on this planet.