The European Space Agency (ESA) is Europe’s gateway to space. Its mission is to shape the development of Europe’s space capability and ensure that investment in space continues to deliver benefits to the citizens of Europe and the world.
Find out more about space activities in our 23 Member States, and understand how ESA works together with their national agencies, institutions and organisations.
Exploring our Solar System and unlocking the secrets of the Universe
Go to topicProtecting life and infrastructure on Earth and in orbit
Go to topicUsing space to benefit citizens and meet future challenges on Earth
Go to topicMaking space accessible and developing the technologies for the future
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Exosat dedicated control room in Darmstadt 1983
Thirty-four years ago, on 26 May 1983, ESA’s Exosat satellite was launched by a Thor-Delta rocket from Vandenburg Airforce Base, California, USA, and was taken over by mission controllers at ESOC, the European Space Operations Centre, Darmstadt, Germany.
Designed to observe and detect high-energy sources, Exosat was the first ESA mission to study the Universe at X-ray wavelengths, and one of the first uncrewed satellites to feature an on-board computer.
By placing the satellite in an elliptical orbit, mission teams were able to operate the instruments for 76 hours of each revolution.
In its three-year life, the mission observed a wide variety of objects, including active galactic nuclei, X-ray binary systems, supernova remnants and clusters of galaxies.
The results that Exosat obtained were very useful to scientists, and led to several new discoveries. The most important of these was probably the discovery of quasi-periodic oscillations in low-mass X-ray binary stars and X-ray pulsars, a phenomenon unknown before Exosat. All the data that Exosat retrieved are still available for study, and are still leading to new discoveries.
In 2017, ESOC is celebrating its 50th anniversary.
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