Paris, 2 March 2004<br />Press Release<br />N° 14-2004<br /><br />Rosetta begins its 10-year journey to the origins of the Solar System<br /><br />Europe's Rosetta cometary probe has been successfully launched into an<br />orbit around the Sun, which will allow it to reach the comet<br />67P/Churyumov-Gerasimenko in 2014 after three flybys of the Earth and one<br />of Mars. During this 10-year journey, the probe will pass close to at<br />least one asteroid. Rosetta is the first probe ever designed to enter<br />orbit around a comet's nucleus and release a lander onto its surface. For<br />over a year it will conduct a thorough study of this remnant of the<br />primitive nebula which gave birth to our Solar System about 5 billion<br />years ago.<br /><br />Rosetta's mission began at 08h17 CET (07h17 GMT) on 2 March when a<br />European Ariane 5 launch vehicle liftered off from the Guiana Space<br />Centre, Europe's spaceport in Kourou, French Guiana. The launcher<br />successfully placed its upper stage and payload into an eccentric coast<br />orbit (200 x 4000 km). About two hours later, at 10h14 CET (09h14 GMT) the<br />upper stage ignited its own engine to reach an escape velocity in order to<br />leave the Earth's gravity field and enter heliocentric orbit. The Rosetta<br />probe was released about 18 minutes later.<br /><br />"After the recent success of Mars Express, Europe is now heading to deep<br />space with another fantastic mission. We will have to be patient, as the<br />rendezvous with the comet will not take place until ten years from now,<br />but I think it's worth the wait" said ESA's Director General Jean-Jacques<br />Dordain witnessing the launch from Kourou.<br /><br />ESA's Operations Centre (ESOC) in Darmstadt, Germany, has established<br />contact with the probe as it flies away from Earth at a relative speed of<br />about 3.4 km/s. ESOC will be in charge of Rosetta operations and orbit<br />determination throughout the mission. During the next eight months, the<br />spacecraft's onboard systems will be checked and its science payload will<br />be commissioned.<br /><br />A 10-year odyssey<br /><br />Rosetta will be reactivated for planetary flybys, which will be used to<br />modify its trajectory through gravity assist manoeuvres. During the trip,<br />the probe could also observe one or more asteroids, observation of<br />asteroids being one of the mission's secondary objectives.<br /><br />The first planetary encounter will be in March 2005, as Rosetta flies by<br />the Earth for the first time. The gravity assist will boost Rosetta into<br />an orbit that will take it to Mars two years later.<br /><br />During its close encounter with Mars in February 2007, Rosetta will<br />approach to a distance of about 200 km and conduct science observations.<br />This Martian flyby will be followed by another Earth flyby in November the<br />same year. Both planetary encounters will increase the probe's orbital<br />energy and boost it well into the asteroid belt.<br /><br />A third and last flyby of the Earth in November 2009 will send Rosetta<br />toward the orbit of comet Churyumov-Gerasimenko.<br /><br />Then, by mid-2011, when it is about 800 million km from the Sun, Rosetta<br />will ignite its main engine for a major deep-space manoeuvre that will<br />place it onto an interception trajectory with the comet, which will take<br />nearly three years to be reached.<br /><br />Rosetta will be reactivated for good in January 2014, as it enters a<br />six-month approach phase, closing in slowly on the nucleus of comet<br />Churyumov-Gerasimenko. The comet will then still be far from the Sun and<br />should not be active.<br /><br />Rendezvous with a comet<br /><br />Like comet 46P/Wirtanen, which was the planned target for Rosetta until<br />its launch was postponed in early 2003, comet 67P/Churyumov-Gerasimenko is<br />one of the periodic comets that were "trapped" in the inner Solar System<br />after they came too close to Jupiter. This comet was discovered in<br />September 1969 at the Almaty Astrophysical Institute in Kazakhstan. It was<br />detected by astronomer Klim Churyumov, from the University of Kiev,<br />Ukraine, on pictures taken by his colleague Svetlana Gerasimenko, from the<br />Institute of Astrophysics of Dushanbe, Tajikistan.<br /><br />Rosetta will start accompanying the comet's nucleus in August 2014. It<br />will then conduct detailed mapping of its surface and a landing site will<br />be selected for Philae, its 100 kg lander. Philae will be dropped from an<br />altitude of about 1 km and, due to the tiny gravity of the nucleus, it<br />will touch down at walking speed. The lander will even have to anchor<br />itself to the surface with two harpoons to avoid bouncing back. Philae is<br />expected to operate from the surface for several weeks, sending back very<br />high resolution pictures and as information about the upper crust of the<br />nucleus. These data will be relayed to Earth by the orbiter.<br /><br />Rosetta will continue its observations of the comet's nucleus for over a<br />year, at least until December 2015, and will have a ringside seat to<br />monitor the « awakening » of the comet's activity as it comes closer to<br />the Sun and reached its perihelion, in October 2015.<br /><br />Probing the comet<br /><br />The Rosetta probe was built for ESA by an industrial team of over 50<br />European companies led by EADS Astrium. It is a 3 tonne spacecraft with<br />solar arrays spanning an impressive 32 metres. This is the first probe<br />designed to travel beyond the orbit of Mars to rely on solar cells for its<br />power supply. In addition to the Philae lander, Rosetta incorporates a 165<br />kg science payload consisting of 11 instruments developed in partnership<br />by ESA member countries and by the the United States.<br /><br />Four of these instruments are dedicated to observation of the nucleus: the<br />ALICE ultraviolet spectrometer, the OSIRIS high-resolution camera, the<br />VIRTIS imaging spectrometer and the MIRO microwave radiometer<br />/spectrometer. Three more instruments will study the composition of the<br />nucleus and its emanations; the COSIMA and ROSINA spectrometers and the<br />MIDAS microscope. The GIADA collector will analyse dusts in the vicinity<br />of the nucleus while the RPC group of sensors will characterise the<br />internal structure of the comet's coma and its interaction with the solar<br />wind. The last two instruments, CONSERT and RSI, will use radio waves, one<br />to probe the internal structure of the nucleus and the other to determine<br />the distribution of masses inside the nucleus and the structure of the<br />coma.<br /><br />The Philae lander, developed under the leadership of Germany's DLR<br />aerospace research agency, carries 9 instruments provided by ESA member<br />countries in partnership with the United States, Hungary and Russia. Among<br />these, the ÇIVA/ROLIS set of cameras will provide panoramic and<br />stereoscopic high-resolution views. The APXS, COSAC and Ptolemy<br />instruments will analyse soil compounds. The SESAME seismometer will probe<br />the surface to a depth of 2 m, while its characteristics will be studied<br />by the MUPUS instrument with sensors on the anchoring harpoon. The ROMAP<br />magnetometer and a second model of the CONSERT experiment will study the<br />magnetic field and its interactions with the solar wind.<br /><br />The Rosetta Stone -unearthed in Egypt more than 200 years ago- gave<br />XIXth-century Egyptologists the keys to decipher hieroglyphic writing and<br />to rediscover three millennia of forgotten Egyptian history and culture.<br />The in-depth study of a comet's nucleus and asteroids by the Rosetta probe<br />is expected to enable today's science community to decipher the mystery of<br />the origins of our Solar System and to better understand the mechanisms<br />ruling the formation of planetary systems around other stars.<br /><br />For more information please contact:<br />ESA Media Relations Division<br />Tel: +33(0) 1 5369 7155<br />Fax: +33(0) 1 5369 7690