Two-phase expendable cooling systems with passive flow control membranes

A system comprising:

• one or more heat sources configured to generate or receive thermal energy;
• and
• a cooling system comprising:
• a heat sink configured to receive the thermal energy from the one or more heat sources, the heat sink comprising a local reservoir configured to hold a liquid coolant, the heat sink configured to pass the thermal energy into the liquid coolant in the local reservoir in order to vaporize at least some of the liquid coolant;
• and
• a membrane configured to allow vaporized coolant to pass through the membrane out of the local reservoir into an ambient environment and to prevent unvaporized coolant from passing through the membrane, the membrane thereby configured to provide passive flow control for the liquid coolant.

A method comprising:

• receiving thermal energy from one or more heat sources at a heat sink;
• passing the thermal energy from the heat sink to a liquid coolant in a local reservoir within the heat sink and vaporizing at least some of the liquid coolant;
• and
• using a membrane, allowing vaporized coolant to pass through the membrane out of the local reservoir into an ambient environment while preventing unvaporized coolant from passing through the membrane, the membrane thereby providing passive flow control for the liquid coolant.