GSFC XMM-Newton GOF Status Report #167: XMM-NEWTON NEWS #85

[xmmnews@lists.nasa.gov]

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_/            XMM-NEWTON NEWS #85   ---    10-Dec-2008            _/
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               XMM-Newton Science Operations Centre at
                ESA's European Space Astronomy Centre,
  P.O. Box - Apdo. 78, 28691 Villanueva de la Canada, Madrid, Spain

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SOC Home Page:
    http://xmm.esac.esa.int/
Helpdesk web interface:
    http://xmm.esac.esa.int/external/xmm_user_support/helpdesk.shtml
Helpdesk email address:
    xmmhelp@sciops.esa.int
News Mailing List:
    http://xmm.esac.esa.int/external/xmm_news/news_list/index.php

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Contents:

   - XMM-Newton Has Resumed Nominal Science Operations with Full
     Efficiency
   - Happy Birthday, XMM-Newton!

XMM-Newton Has Resumed Nominal Science Operations with Full Efficiency
======================================================================

A new operational concept has been successfully defined and
implemented for the XMM-Newton Observatory. This followed the loss
of contact on the 18th of October 2008 and subsequent recovery on
the 22nd. In November, astronomical observations were performed
using only one of the two on-board antennas to communicate with the
Earth and taking advantage of the favourable celestial geometry
(see Newsletter #83, available at
http://xmm.esac.esa.int/external/xmm_news/news_list/xmm_news-2008-10-28.shtml).

With the new strategy, XMM-Newton is once again able to fully
utilise the available science windows and operate with the
efficiency achieved before the anomaly. The definition of the new
operational concept has been the result of several experts from ESA
and industry working together on the evaluation of the advantages
and disadvantages of different possible scenarios. A number of
tests have been performed during which XMM-Newton was always safe
and fully under the control of the mission control team at ESOC,
while the instrument health was being monitored by the science
operations team at ESAC. When the best strategy was identified, the
mission planning team at ESAC made a very fast and efficient update
of the planning software to include the new constraints and the
team at ESOC modified their validation routines accordingly. This
has made it possible to run a test revolution which started on the
1st of December and after its success, to declare this new mode as
operational and start using it on December 5.

The net impact of the non-standard November operations on observing
time has been of the order of 370 ks lost in slightly more than one
month. This is 20% of the observing time that would have been
available in that month with the nominal efficiency. If we add the
seven revolutions lost earlier due to the loss of contact, the
final time lost is about 6% of the total time available in one year.
No further impact is expected in the future other than mission
planning being slightly more complex, but this in the end is
expected to have little, or no impact on XMM-Newton users.

We are therefore glad to inform you that XMM-Newton has gone
through her 9th anniversary perfectly in shape.


Happy Birthday, XMM-Newton!
===========================

We take the opportunity to remind you that today marks another
anniversary of XMM-Newton: on December 10th at 14:32 GMT it is
exactly nine years ago that the European Space Agency's XMM-Newton
observatory was placed into its orbit and started exploring the
wonders of the X-ray universe.


Yours sincerely,
XMM-Newton SOC

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