At present the European Space Agency is working on one of its Cornerstone Missions, named "Rosetta", to be launched in January 2003 for a visit to comet 46P/Wirtanen2 in 2011. The Rosetta spacecraft will carry a small subsatellite, the Rosetta Lander3 (RoLand), to be detached from the orbiter and land on the surface of the comet's nucleus. One of our main scientific interests is to find out whether chiral organic compounds in cometary matter brought to the Earth by cometary impacts might have had, due to corresponding enantiomeric excesses, a seed function in determining the handedness which is characteristic of homochiral compounds employed by life on Earth. For this reason we have developed an Experiment for the ROSETTA mission, named Cometary Sampling and Composition Experiment (COSAC).