XMM-Newton Users Handbook

4.1 XMM-Newton orbit

XMM-Newton was launched on the 10th December 1999 by an Ariane 5 launcher into a highly elliptical orbit, with an apogee of about 115,000 km and a perigee of ca. 6000 km (Fig. 101). XMM-Newton is operated with three ground stations, located at Perth, Kourou and Santiago de Chile (occasionally also ESAC, Madrid, Spain).

Figure 101: Sketch of the highly elliptical XMM-Newton orbit. Original figure provided by Dornier Satellitensysteme GmbH.

Due to several perturbations, the orbit of XMM-Newton changes with time. In addition, an orbit correction manoeuvre was performed in February 2003 to ensure full ground station coverage during the entire science period. The orbital parameters for May 2010 are listed in Table 27. Such an orbit provides the best visibility in the southern celestial sky (§ 4.2.3).

Table 27: Orbital Parameters of XMM-Newton for May 2010 (last update: June 2009)

Inclination	60.6	$^\circ$
Right ascension of ascending node	93.6	$^\circ$
Argument of perigee	112.6	$^\circ$
Apogee height	107,230	km
Perigee height	26,700	km
Eccentricity	0.60
Period	47.86	hours