[meteorite-list] Rosetta Begins Its 10-Year Journey To Comet Churyumov-Gerasimenko

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 10:32:45 2004
Message-ID: <200403021624.IAA15392_at_zagami.jpl.nasa.gov>

European Space Agency
Paris, 2 March 2004
Press Release
N° 14-2004

Rosetta begins its 10-year journey to the origins of the Solar System

Europe's Rosetta cometary probe has been successfully launched into an
orbit around the Sun, which will allow it to reach the comet
67P/Churyumov-Gerasimenko in 2014 after three flybys of the Earth and one
of Mars. During this 10-year journey, the probe will pass close to at
least one asteroid. Rosetta is the first probe ever designed to enter
orbit around a comet's nucleus and release a lander onto its surface. For
over a year it will conduct a thorough study of this remnant of the
primitive nebula which gave birth to our Solar System about 5 billion
years ago.

Rosetta's mission began at 08h17 CET (07h17 GMT) on 2 March when a
European Ariane 5 launch vehicle liftered off from the Guiana Space
Centre, Europe's spaceport in Kourou, French Guiana. The launcher
successfully placed its upper stage and payload into an eccentric coast
orbit (200 x 4000 km). About two hours later, at 10h14 CET (09h14 GMT) the
upper stage ignited its own engine to reach an escape velocity in order to
leave the Earth's gravity field and enter heliocentric orbit. The Rosetta
probe was released about 18 minutes later.

"After the recent success of Mars Express, Europe is now heading to deep
space with another fantastic mission. We will have to be patient, as the
rendezvous with the comet will not take place until ten years from now,
but I think it's worth the wait" said ESA's Director General Jean-Jacques
Dordain witnessing the launch from Kourou.

ESA's Operations Centre (ESOC) in Darmstadt, Germany, has established
contact with the probe as it flies away from Earth at a relative speed of
about 3.4 km/s. ESOC will be in charge of Rosetta operations and orbit
determination throughout the mission. During the next eight months, the
spacecraft’s onboard systems will be checked and its science payload will
be commissioned.

A 10-year odyssey

Rosetta will be reactivated for planetary flybys, which will be used to
modify its trajectory through gravity assist manoeuvres. During the trip,
the probe could also observe one or more asteroids, observation of
asteroids being one of the mission's secondary objectives.

The first planetary encounter will be in March 2005, as Rosetta flies by
the Earth for the first time. The gravity assist will boost Rosetta into
an orbit that will take it to Mars two years later.

During its close encounter with Mars in February 2007, Rosetta will
approach to a distance of about 200 km and conduct science observations.
This Martian flyby will be followed by another Earth flyby in November the
same year. Both planetary encounters will increase the probe's orbital
energy and boost it well into the asteroid belt.

A third and last flyby of the Earth in November 2009 will send Rosetta
toward the orbit of comet Churyumov-Gerasimenko.

Then, by mid-2011, when it is about 800 million km from the Sun, Rosetta
will ignite its main engine for a major deep-space manoeuvre that will
place it onto an interception trajectory with the comet, which will take
nearly three years to be reached.

Rosetta will be reactivated for good in January 2014, as it enters a
six-month approach phase, closing in slowly on the nucleus of comet
Churyumov-Gerasimenko. The comet will then still be far from the Sun and
should not be active.
Rendezvous with a comet

Like comet 46P/Wirtanen, which was the planned target for Rosetta until
its launch was postponed in early 2003, comet 67P/Churyumov-Gerasimenko is
one of the periodic comets that were "trapped" in the inner Solar System
after they came too close to Jupiter. This comet was discovered in
September 1969 at the Almaty Astrophysical Institute in Kazakhstan. It was
detected by astronomer Klim Churyumov, from the University of Kiev,
Ukraine, on pictures taken by his colleague Svetlana Gerasimenko, from the
Institute of Astrophysics of Dushanbe, Tajikistan.

Rosetta will start accompanying the comet's nucleus in August 2014. It
will then conduct detailed mapping of its surface and a landing site will
be selected for Philae, its 100 kg lander. Philae will be dropped from an
altitude of about 1 km and, due to the tiny gravity of the nucleus, it
will touch down at walking speed. The lander will even have to anchor
itself to the surface with two harpoons to avoid bouncing back. Philae is
expected to operate from the surface for several weeks, sending back very
high resolution pictures and as information about the upper crust of the
nucleus. These data will be relayed to Earth by the orbiter.

Rosetta will continue its observations of the comet's nucleus for over a
year, at least until December 2015, and will have a ringside seat to
monitor the "awakening" of the comet's activity as it comes closer to
the Sun and reached its perihelion, in October 2015.

Probing the comet

The Rosetta probe was built for ESA by an industrial team of over 50
European companies led by EADS Astrium. It is a 3 tonne spacecraft with
solar arrays spanning an impressive 32 metres. This is the first probe
designed to travel beyond the orbit of Mars to rely on solar cells for its
power supply. In addition to the Philae lander, Rosetta incorporates a 165
kg science payload consisting of 11 instruments developed in partnership
by ESA member countries and by the the United States.

Four of these instruments are dedicated to observation of the nucleus: the
ALICE ultraviolet spectrometer, the OSIRIS high-resolution camera, the
VIRTIS imaging spectrometer and the MIRO microwave radiometer
/spectrometer. Three more instruments will study the composition of the
nucleus and its emanations; the COSIMA and ROSINA spectrometers and the
MIDAS microscope. The GIADA collector will analyse dusts in the vicinity
of the nucleus while the RPC group of sensors will characterise the
internal structure of the comet's coma and its interaction with the solar
wind. The last two instruments, CONSERT and RSI, will use radio waves, one
to probe the internal structure of the nucleus and the other to determine
the distribution of masses inside the nucleus and the structure of the

The Philae lander, developed under the leadership of Germany's DLR
aerospace research agency, carries 9 instruments provided by ESA member
countries in partnership with the United States, Hungary and Russia. Among
these, the ÇIVA/ROLIS set of cameras will provide panoramic and
stereoscopic high-resolution views. The APXS, COSAC and Ptolemy
instruments will analyse soil compounds. The SESAME seismometer will probe
the surface to a depth of 2 m, while its characteristics will be studied
by the MUPUS instrument with sensors on the anchoring harpoon. The ROMAP
magnetometer and a second model of the CONSERT experiment will study the
magnetic field and its interactions with the solar wind.

The Rosetta Stone - unearthed in Egypt more than 200 years ago - gave
XIXth-century Egyptologists the keys to decipher hieroglyphic writing and
to rediscover three millennia of forgotten Egyptian history and culture.
The in-depth study of a comet's nucleus and asteroids by the Rosetta probe
is expected to enable today's science community to decipher the mystery of
the origins of our Solar System and to better understand the mechanisms
ruling the formation of planetary systems around other stars.

For more information please contact:
ESA Media Relations Division
Tel: +33(0) 1 5369 7155
Fax: +33(0) 1 5369 7690



Rosetta On Its Way
European Space Agency
March 2, 2004

After two previous launch attempts had been postponed Rosetta finally set
off on its long journey to comet 67/P Churyumov-Gerasimenko at 0717 UT 2
March 2004. Arianespace Flight 158, with its Ariane 5 rocket and modified
upper stage, successfully placed Rosetta onto an escape trajectory and out
into the solar system.

1330 UT
The solar panels have now been successfully
deployed and the spacecraft is receiving power
through them.

0937 UT
ESOC takes over control of the mission and begins
communicating with the spacecraft.

0933 UT
Successful separation of the Rosetta spacecraft.

0932 UT
Shut down of the EPS stage on schedule at an
altitude of around 1200 km and a velocity of around
10 250 ms-1.

0928 UT
Signal acquisition at the Kourou tracking station
confirms an altitude of 750 km and a velocity of 10
180 ms-1. Rosetta is looking good for separation in
a couple of minutes time.

0916 UT
Ignition of the EPS upper stage at an altitude of
around 550 km and a velocity of 7500 ms-1. By the
end of the 17 minute engine burn Rosetta will be
travelling at over 10 000 ms-1.

0904 UT
Acquisition of signal at the South Point Tracking
Station Hawaii.

0805 UT
Acquisition of signal at the Dongara tracking
station in Australia.

0729 UT
Ariane 5 has moved into a ballistic phase. The
main cryogenic stage having burnt all its fuel has
been jettisoned. Rosetta and the upper stage of
Ariane 5 have now gone into orbit around the Earth
starting from an altitude of 250 km. During the
orbit the combined upper stage and spacecraft will
reach a peak altitude of 4000 km before coming
back closer to the Earth. At around 0910 UT the
upper stage will fire accelerating the Rosetta
spacecraft to escape velocity and out into the Solar

0725 UT
Acquistion by tracking station at Natal

0720 UT
Booster stages have been successfully jettisoned

0717 UT
Ariane 5 Flight 158 powers off the launch pad and
Rosetta begins her journey to 67/P

0710 UT
"All systems go" and start of the synchronised

0607 UT
Checks of the connections between launcher and
telemetry, tracking and command systems have
just taken place.

2 March 0357 UT
Chilldown of Vulcain main stage engine

2 March 0227 UT
Start of filling of main cryogenic stage with liquid
oxygen and hydrogen.

1 March 2347 UT
Check of electrical systems

1 March 1947 UT
Start of final countdown
Received on Tue 02 Mar 2004 11:24:45 AM PST

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