Thermal management systems

A thermal management system, comprising:

• a receiver that comprises an inlet and an outlet, the receiver configured to store a refrigerant fluid at a first pressure that is a greater than a critical point pressure of the refrigerant fluid;
• at least one flash tank that comprises an inlet fluidly coupled to the outlet of the receiver, a vapor-side outlet, and a liquid-side outlet;
• an expansion valve that comprises an inlet fluidly coupled to the liquid-side outlet of the flash tank, the expansion valve configured to expand the refrigerant fluid from the flash tank to a second pressure that is less than a triple point pressure of the refrigerant fluid to form a solid-vapor mixture of the refrigerant fluid;
• an evaporator comprising an inlet positioned to receive the solid-vapor mixture of the refrigerant fluid and configured to extract heat from at least one heat load that is in at least one of thermal conductive or convective contact or is in proximity to the evaporator, the evaporator further configured to sublimate a solid state of the solid-vapor mixture of the refrigerant fluid directly into a vapor state of the refrigerant fluid;
• and
• an exhaust conduit fluidly coupled to an outlet of the evaporator, the exhaust conduit configured to discharge the vapor state of the refrigerant fluid into an ambient environment without returning the vapor state of the refrigerant fluid from the outlet of the evaporator to the receiver.