Herschel Space Observatory - An ESA facility for far-infrared and submillimetre astronomy G. L. Pilbratt, J. R. Riedinger, T. Passvogel, G. Crone, D. Doyle, U. Gageur, A. M. Heras, C. Jewell, L. Metcalfe, S. Ott and M. Schmidt A&A, 518 (2010) L1 Published online: 16 July 2010 DOI: 10.1051/0004-6361/201014759