ESA Science News

The XMM-Newton space observatory has formally been handed over to the science team that will be
operating it for the years to come. Following a commissioning phase review, held at the mission’s
Science Operations Centre in Villafranca on 8/9 March, ESA management has declared that the
commissioning of the spacecraft and the instruments is completed. Operations can now commence
with the start of the calibration of its science instruments, essential before regular science
observations can begin in June.

The commissioning phase which checked out and tested the spacecraft and its instruments began on 4
January. Since that date, the satellite has shown that it is functioning in orbit entirely as planned and
that its X-ray and optical cameras are living up to expectations, as was vividly shown in the very first
images officially presented on 9 February.

The successful end of commissioning means, in effect, that the European Space Agency can now
formally recognise that prime contractor Dornier Satellitensysteme has fulfilled its part of the contract.
It also confirms that the mission’s ground infrastructures, the Mission Operations Centre at ESOC in
Darmstadt controlling the satellite and the Science Operations Centre VILSPA in Villafranca receiving
and processing the science data, are ready for the operational phase.

The contractual milestone of successful commissioning and the start of the calibration phase was
approved during a final meeting at ESTEC on 13 March with John Credland and Martin Huber,
respectively Head of ESA’s Scientific Programme and Space Science Departments. From this moment,
responsibility for the mission passed from the ESA XMM-Newton Project Manager to the mission’s
Project Scientist, a hand-over that Robert Lainé symbolically marked by giving Fred Jansen an antique
wrought-iron key that he had found in Spain.

“The development phase is over — said Robert Lainé — we have delivered the product, a unique
observatory that is up and running. Our part of the job, which for some of us started way back in the
late 80s, is done. It is now up to your science teams to fine-tune the instruments for the start of full
science operations this summer.”

Over the course of the next two months the calibration phase will proceed rigorously, with a series of
observations of celestial targets whose characteristics are known and/or understood such that the
performance of XMM can be measured and quantified. During this process a certain flexibility will be
maintained to focus on astronomical events or phenomena that might suddenly arise. “We will be
comparing the performance of XMM-Newton as it observes new X-ray sources to what we already
know about well referenced sources, establishing the exact performance of the instruments down to
the percentage level. It is only when we master their precise behaviour that we will be able to extract
valid data and start interpreting results.”

Fred Jansen acknowledges that whilst guest observers are impatient to start using the observatory,
he and all the Principal Investigators know that an accurate calibration is crucial. “It is as though
Robert Lainé and his team had given us the best television set with a 100 channels, but now we must
be sure to get nice programmes to show on it!”


* Commisioning XMM-Newton



XMM-Newton project manager Robert Laine (left) handing over the
‘XMM-Newton key’ to project scientist Fred Jansen.