A thermal management system includes a closed-circuit refrigeration system (CCRS) that includes a vapor cycle system (VCS). The VCS includes a receiver configured to store a refrigerant fluid; a liquid separator; a compressor; a condenser; at least one evaporator configured to extract heat from at least one heat load that is in thermal conductive or convective contact with the evaporator; and a thermal energy storage (TES) that stores a phase change material. The thermal management system further includes a liquid pumping system (LPS) that includes the TES, the at least one evaporator, and the liquid separator, with the LPS further including a pump. The VCS is configured to operate one at a time in at least one of three operational modes that are a TES cooling mode, a heat load cooling mode, or a pump-down mode. The LPS is configured to operate in the heat load cooling mode.