Rosetta Lander, a Research Station on a Comets Nucleus

The ESA cornerstone mission Rosetta to Comet P/Wirtanen, includes a Lander with an overall mass of about 85 kg. After arrival of the Rosetta main spacecraft at the comet and an extensive mapping phase, the Lander will be ejected and descend, supported by a vertical thruster to the surface of the nucleus at a solar distance of 3 AU. A specially designed landing gear and a harpoon anchoring device, which will be fired immediately after touch-down, will prevent rebounding. After an initial condensed scientific measurement sequence of five days, the lander will operate for several months and collect information on the surface properties of P/Wirtanen as a function of time and distance to the sun. The selected complement of scientific instruments with an overall mass of about 20 kg will determine the chemical, physical, and mineralogical properties of the surface material, provide images, and also investigate the internal structure of the nucleus. A drill and sampling device will collect subsurface material and deliver it to some of the instruments.