The XMM-Newton observatory is the biggest science satellite
ever built in Europe, and is ESA's second cornerstone of its
Horizon 2000 program. Its name derives from its three X-ray
telescopes, each containing 58 high-precision concentric
Fully assembled, XMM-Newton stands ten meters
tall. It is shown here during acoustic testing at
ESTEC in July
The spacecraft consists of three main sections:
- a seven meter long black telescope tube;
- a squarish service module also carrying three 'mirror modules' at
its forward broader end;
- the focal plane assembly housing the X-ray cameras and detectors
at its other extremity.
This 'tri-clops' with its golden eyes is more than 10 meters long, just
able to fit into the payload bay of the Ariane-5 rocket. XMM-Newton
receives power through its pair of solar panels, giving it a
16 meter "wing" span.
The spacecraft's design features extremely high mechanical stability. Its
position and control systems allow it to point at targets in the sky over
long periods with a remarkable pointing accuracy of 0.25 arcsec over a ten
second interval. This is about 1/8000th the diameter of the
Moon in the sky, or equivalent to using a
hand-held telescope and clearly seeing a melon placed 180 km
The space observatory was built in conditions of exceptional
cleanliness to preserve its ultra-polished mirrors. Another requirement
was its light-tightness to avoid extraneous light.
The XMM-Newton program, with the parallel construction of two models and the
manufacture of the proto-flight model, was conducted in the space of just
less than three years. Most of the testing was done on a modular basis,
and the calibration of its mirror modules required a custom-built
vertical test facility.
XMM-Newton weighed 3.8 tons on the launch pad. It was designed to
operate for at least two years in orbit, and it has already exceeded
this specification. It is expected to be operational for many more
years; the hydrazine propellant aboard its service module could be enough
for a total lifetime of ten years.
If you have any questions concerning XMM-Newton send e-mail to email@example.com.