The Herschel/Planck programme - technical challenges for two science missions

The two science missions Herschel, an observatory-type mission, and Planck, a survey mission, are combined in one program within the long-term science program of the European Space Agency (ESA). Herschel is an observatory-type mission, which targets the largely unexplored infrared and sub-millimeter part of the electromagnetic spectrum, from 60 to 670 microns, with one of the key objectives being to explore the formation of galaxies and stars. Planck is a survey mission dedicated to image the whole sky simultaneously in nine frequency channels between 30 and 900 GHz to unravel the temperature fluctuations of the cosmic background radiation. Both spacecraft was launched from the European spaceport in Kourou, French Guiana, on a single Ariane 5 launcher in February 2007 to the 2nd Lagrangian Point L2 of the Earth-Sun system.