1990-1993:   European Committee for Future Accelerators, EFCA

since 2000:   Physics Working Group of SCAR (Scientific Committee on Antarctic Research)

2001-2010:   External Review Committee of ANTARES

since 2003:   Peer Review Committee of ApPEC (Astroparticle Physics European Coordination)

since 2006:   Chair of the ApPEC Peer Review Committee

2003-2006:   Chair of the R.W. Pohl Price Committee, DPG

2003-2006:   External Review Committee APC (Paris)

since 2007:   Komitee für Astroteilchen-Physik, KAT

since 2010:   KAT Vorsitz

since 2008:   PANAGIC (Particle And Nuclear Astrophysics and Gravitational International Committee)

since 2008:   Editorial Board of the European Journal of Physics C

since 2009:   CERN Science Policy Committee

2009 :   Particle Astrophysics Scientific Assessement Group (PASAG) to NSF and DOE

since 2009:   Science Advisory Committee of the Modane Underground Laboratory

2009-2010:   OECD Global Science Forum: Working Group on Astroparticle Physics

since 2011:   KM3NeT Science Advisory Committee