This article is about XMM-Newton. If you are searching for XMM registers found on Intel SSE, see SSE The XMM-Newton (X-ray Multi-Mirror Mission - Newton) is an orbiting X-rayobservatory, named in honor of Isaac Newton.Originally known as the High Throughput X-ray Spectroscopy Mission, it was launched by the European Space Agency from Kourou on December 10, 1999 by an Ariane 5 rocket. It was placed in a very eccentric 48 hour elliptical orbit at 40°; at its apogee it is nearly 114,000 km from Earth, while the perigee is only 7,000 km.
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