Thursday, August 14, 2014

The constraints of the landing of Philae

In the coming weeks, although scientific observations are planned, Rosetta will mainly tackle to best prepare for the landing of Philae , a small lander conducted by an international consortium, under the responsibility of Germany and CNES main partner .

The constraints of the landing of Philae

"As it stands, the nucleus of the comet is a concern for landing. " Even on an ordinary comet, find a place that is not too rough and slopes that do not endanger the landing is really not easy so with a "form like that of the comet that becomes very complicated " . This site will be determined in the coming weeks, from the data collected and a number of parameters to be observed.

Like the Nasa , who asked the Curiosity rover inside Gale Crater, there are just two years, August 6, 2012, the goal is to position Philae "ellipse of uncertainty" 3 sigma "represents an area one kilometer inside the probe which has a 99% chance to land" . Also, given the shape of the core account, "this position a mile is all the more complicated because of the many specific constraints Philae ellipse".

Artist's release of Philae, which will be from a distance of only 2.5 km above the surface of the comet. © Esa

The main problem is the size of the comet four kilometers at its longest. Philae will "have to aim at a point inside the ellipse and get around 500 meters. This will require to study the trajectory " . The 3D models of the shape of the kernel will create successively Laboratoire d ' Astrophysique de Marseille (Aix-Marseille University) will be very useful. Especially since the precision of the landing is not the only concern of ground controllers.