Space suits are primarily cooled using a system that circulates liquid close to the astronaut's body.
For example, in Space Shuttle space suits, also known as Extravehicular Mobility Units or EMUs, astronauts stay cool thanks to an integrated cooling system. This system is designed to manage the significant heat generated by the human body during strenuous activity in the vacuum of space.
The EMU Cooling System Explained
The cooling process in Space Shuttle EMUs relies on a specific setup:
- Network of Tubes: The cooling system consists of a network of small diameter tubes.
- Water Circulation: These tubes circulate water (or sometimes a cooling fluid) throughout the suit.
- Close Contact: The tubes are strategically placed and held close to the astronaut's body.
- Spandex Body Suit: This is achieved by integrating the tubes into or holding them against the body with a snug-fitting Spandex® body suit worn underneath the main pressure garment.
As the astronaut's body generates heat, this heat is transferred to the circulating water in the tubes. The water then carries the heat away to a heat exchanger within the portable life support system (PLSS) unit attached to the suit. The heat exchanger releases the heat into space, often through sublimation of ice or direct radiation, thus maintaining a comfortable temperature for the astronaut inside the suit.
This method ensures that the astronaut does not overheat, even while performing demanding tasks during spacewalks (Extravehicular Activities - EVAs).
