Start at 12:30pm
By Jean-Pierre Lebreton, Research scientist, LPC2E, CNRS-University of Orleans. Member of the Air and Space Academy
Rosetta, which is made up of a main spacecraft and a lander, Philae, was launched by an Ariane-5 rocket from Kourou in March 2004. After travelling through the solar system for over ten years, the mission has been operational since April 2014, at which point it was several million kilometres away from Comet 67P/Churyumov-Gerasimenko. Rosetta arrived on time for its rendezvous with the comet in early August, at a distance of less than 100 km. On 12 November, Philae carried out a successful, if slightly chaotic, landing on the surface of the comet. The main ship follows a complex path around the comet dictated by operational constraints related to the spacecraft's interaction with the gas and dust environment of the comet. In September-November 2014, in circular orbit close to the surface (at distances of between 10-30 km above the nucleus), Rosetta yielded an exceptional crop of data. In February then March 2015, Rosetta followed a pyramidal path which included a flyover around 10 km above the nucleus. These close encounters – one of Rosetta's many major firsts – proved tricky to manage operationally. The next flyovers will remain further from the surface. Rosetta is escorting the comet on its path around the sun and observing how its activity varies as the comet approaches and then recedes from the sun. The mission, initially planned to last until December 2015 (at a distance of 2AU from the sun), could be extended several months in order to observe the reduction in the comet's activity as it draws away from the sun to a distance of approximately 3AU. The first results, published in the scientific journals "Science" and "Nature" in late January, as well as those obtained by Philae at the time of publication, have lifted the veil on the first secrets of 67P. The mission and a summary of the first observations will be presented.
Free entry, registration required