A Fortran-language computer program for simulating the operation of a water-cooled vapor-compression heat pump in any orientation with respect to gravity has been developed by modifying a prior general-purpose heat-pump design code used at Oak Ridge National Laboratory (ORNL). Al - though it is specific to the design of a high-temperature-lift heat pump for the International Space Station, this program could serve as a basis for development of general-purpose computational software for designing and analyzing liquid-cooled heat-pumps. The ORNL program contained models of refrigerant-fluid-to-air heat exchangers; the main modification consisted in replacing those models with models of plate-type heat exchangers utilizing water as both the cooling and the heating source liquid.