[meteorite-list] Rosetta Update - February 28, 2005

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Mon Mar 21 13:24:53 2005
Message-ID: <200503032254.j23MsHm14880_at_zagami.jpl.nasa.gov>

http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=36631

Earth Fly-by Approaches
European Space Agency
Rosetta
February 28, 2005

Report for the period 14 to 24 February 2005

The main activity of the reporting period was the last trajectory
correction manoeuvre before Earth swing-by. The manoeuvre was executed
successfully on 17 February and has put the spacecraft onto its final
course to Earth. Thanks to the precision of the manoeuvre execution it
was not necessary to use the back-up manoeuvre slot planned for 24 February.

The first Earth swing-by will take place on 4 March 2005 at around 22h10
UT, when the spacecraft will be 1900 km from the surface. Rosetta will
approach from the direction away from the Sun and have its closest
approach on the illuminated side of the Earth. As the spacecraft
approaches, it will seem to fly to the west and will disappear on the
dayside of the Earth.

Preparation activities for the Earth swing-by included two simulations
scheduled to train the team into contingency operations with the special
spacecraft configuration around closest approach. Validation activities
of the whole scenario, and in particular of the Asteroid Flyby Mode test
with the Moon, planned for 5 March, continued using the EQM, the
Simulator and involved some simulation runs on the Rosace tool by
Astrium at Toulouse. A Go for AFM Test with the Moon was decided in a
readiness meeting on 22 February.

The frequency of New Norcia passes is now almost daily, in support of
the orbit manoeuvres and to increase tracking data recovery for precise
orbit determination. For the same reason, as from 14 February daily DSN
passes are taken (typically 4 hours each).

The table below shows a chronology of the main activities in the
reporting period (only active passes shown):

Mission Date DOY Main Activity
 Day'

 350 14.02.05 045 Tracking pass
 351 15.02.05 046 Switch STR A off and ACM-B On
 352 16.02.05 047 Monitoring pass
 353 17.02.05 048 Trajectory Correction Manoeuvre 6
 354 18.02.05 049 Monitoring pass
 356 20.02.05 051 Tracking pass
 357 21.02.05 052 Tracking pass
 358 22.02.05 053 Monitoring pass
 359 23.02.05 054 Monitoring pass
 360 24.02.05 055 Monitoring pass

At the end of the last New Norcia pass in the reporting period (DOY 056)
Rosetta was at 2.76 million km from the Earth. The one-way signal travel
time was 9.2 seconds.
Received on Thu 03 Mar 2005 05:54:16 PM PST