Once the goals of the PV and science demonstration phases have been met, Herschel will go into the routine science operations phase for a minimum of 3 years. Early on, mainly Guaranteed Time and "Key Project" observing programmes will be performed. Key Projects will be performed early in the mission to permit follow-up and to give the Guaranteed Time holders at the HSC the opportunity to obtain real data to work with, in preparation for supplying community support to the open time observers with the benefit of a thorough knowledge of the entire observing chain from proposal submission to access and reduction of data.

All observers will be able to track the whereabouts of their proposals and will be notified when the resulting data can be accessed.