The Hermes manipulation system (HERA) is a sophisticated space manipulator system, which has to perform tasks ranging from berthing to tool operation in various operational modes from fully automatic to purely manual. The HERA system main contractor is Fokker Space & Systems B.V. (FSS). Development and qualification of such a space-based manipulator must be supported by computer simulation facilities. The National Aerospace Laboratory (NLR) in the Netherlands is responsible for the development of the so-called HERA Simulation Facilities (HSF). The paper will focus on the HSF-P; a first 'pilot' real-time simulation facility.