"Scheduled on 6 May from Kourou, the launch of the Herschel and Planck space observatories, in this International Year of Astronomy, will be a key moment for the European Space Agency. The spacecraft constitute together the most important space science programme that ESA has ever undertaken. The two missions, observing in different wavelengths, will complete the observations of other space and ground observatories, helping to draw up a complete picture of the electromagnetic spectrum.