[meteorite-list] Rosetta Mars Swing-by

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Fri, 23 Feb 2007 22:56:51 -0800 (PST)
Message-ID: <200702240656.WAA13026_at_zagami.jpl.nasa.gov>

http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=40697

Rosetta Mars Swing-by
European Space Agency
23 Feb 2007

The Rosetta swing-by of Mars is the second of four gravity assist
manoeuvres that are required to place Rosetta on course for
its final destination: comet 67P/Churyumov-Gerasimenko. The
closest approach of the swing-by will take place at 01:54 UT,
25 February 2007, when the spacecraft will pass 250 km above
the surface of Mars.

Updates on the progress of the flyby can be found on the ESA
Rosetta Swing-by site.

The Mars swing-by has been setup by two deep space manoeuvres
on 29 September 2006 and 13 November 2006 and a trajectory control
manoeuvre on 9 February 2007 to accurately set Rosetta on the
required swing-by path.

Dates of Assist Manoeuvres

The Mars swing-by has been setup with two Deep Space Manoeuvres
on 29 September 2006 and 13 November 2006 and a Trajectory Control
Manouevre on 9 February 2007 to accurately set Rosetta on the
required swing-by path (see related status reports on the right
hand side).
Mars Swing-by Details

Event Time (UT)
Occultation Start 01:52:24
Closest Approach 01:54:12
Eclipse Start 01:54:25
Occultation End 02:06:50
Eclipse End 02:19:10

The time of closest approach is at approximately 01:54 UT, when
Rosetta is only 250 km above the Martian surface and traveling
at a speed of over 36 000 kmh-1 relative to Mars. The swing-by
takes Rosetta over Mars's northern hemisphere, with the point
of closest approach of a surface position of 298.2? E and 43.5?
N.

During the swing-by, Rosetta will pass behind Mars, as seen
from Earth, resulting in a loss of communication for a period
of 15 minutes, starting 2 minutes before closest approach.

In addition, Rosetta will pass through the shadow cast by Mars
for a period of 25 minutes and go into eclipse. For this reason
the spacecraft instruments are not active at closest approach
- except for the Radio Science experiment. Power will be provided
by the spacecraft's batteries.

Planned Science Activities

Mars
Between 8 hours and 4 hours prior to closest approach, the orbiter
instruments will perform targeted observations of the Martian
surface and the two moons of Mars, Phobos and Deimos.

Because Philae runs off its own separate power supply it is
possible to have some of these instruments active during the
eclipse phase. At closest approach the ROMAP and CIVA instruments
will be operated. ROMAP (Rosetta Lander Magnetometer and Plasma
Monitor) will take magnetometric measurements from 12 hours
before to 12 hours after closest approach. CIVA (Comet Nucleus
Infrared and Visible Analyser) will perform imaging of Mars.

Activity Instrument
Mars spectroscopy and imaging of surface and atmosphere OSIRIS
        Orbiter
ALICE Orbiter
VIRTIS Orbiter
CIVA Lander Philae
Investigating the interaction of Mars with the solar wind Rosetta
Plasma experiment Orbiter
ROMAP Lander Philae
OSIRIS Orbiter
Phobos and Deimos imaging OSIRIS Orbiter
Searching for anomalous accelerations during the swing-by

Radio Science experiment
        Orbiter
Investigating the Mars radiation environment

Radiation Monitor
experiment
        Orbiter

Jupiter
On 27 February, only a few days after Rosetta's closest approach
to Mars, NASA's New Horizon spacecraft will perform a swing
by of Jupiter and afterwards will fly along the planet's magnetotail
for about 100 days.

Due to Sun illumination conditions, Rosetta will be able to
observe Jupiter for 4 hours on 28 February and continuously
after 1 March. Rosetta will make Jupiter observations with the
ALICE, VIRTIS and OSIRIS instruments.

Pioneer Anomaly
First observed with the NASA Pioneer spacecraft, the anomaly
represents a deviation in the expected change in spacecraft
velocity and trajectory against observations. Scientist are
not certain if the anomaly is caused by an unknown physical
process, or if it is simply down to the uncertainties in measurements
and analytical calculations. A test will be carried out using
a MASER signal sent from the ground based tracking stations.
Received on Sat 24 Feb 2007 01:56:51 AM PST