a hermetically sealed suit that makes it possible for persons to pursue normal activities and work efficiently under abnormal conditions. The suit usually consists of an envelope suit, a helmet, gloves, and shoes. The breathing mixture may be fed into the suit from an outside source, such as a gas cylinder, or it may be processed by regeneration. With regeneration, the exhaled gas is purified in a special cartridge where carbon dioxide and moisture are removed, and the gas is enriched with oxygen and then fed into the suit. Protective suits include diving suits (seeDIVING) and space suits.
Space suits are classified as emergency rescue suits, suits for walking in free space, and suits for use on the surface of the moon and planets. Emergency rescue suits are used by cosmonauts during any failure of the hermetic seals in the cabin of a spacecraft. They are also used if the parameters of the atmosphere in the cabin deviate from the specified values. Suits for walking in free space protect cosmonauts from micrometeorite particles, prevent overheating on the sunlit side of the suit and overcooling in the shade, and protect the eyes from solar radiation. The suit may be connected to the spacecraft with a flexible hose, through which the breathing mixture is supplied, or it may be equipped with a self-contained life-support system.
Space suits for use on the surface of the moon and planets are so constructed that the cosmonaut can walk or rise after a fall unassisted. They may be soft or rigid. The heavy-duty envelope of a soft space suit is made of fabric. In the absence of pressure inside the suit, the envelope clings to the body without interfering with movement. Rigid space suits have a hard metal or plastic shell conforming approximately to the shape of the body and hinges at the body joints.
The soft space suit used by the USA for lunar exploration consists of an outer layer, thermal insulation with a combination shield and vacuum layer, a protective layer against meteors, protective, heavy-duty, and hermetically sealed envelopes, a ventilating system, a helmet, a cooling system, and shoes. The outer layer protects the suit from mechanical damage and reflects the sun’s radiant energy. It is made of a white, heat-resistant fabric, such as fiber glass. The thermal insulation is beneath the outer layer and consists of several layers of thin film with an aluminized surface; the layers are separated by a fiberglass mesh. Protection from micrometeorite particles is provided by the suit as a whole and by a special suit made of felt or a rubberized synthetic fabric. The hermetically sealed envelope is made of rubber or a rubberized fabric. The cooling system includes a suit with a water-cooling or evaporation system. The helmet is fitted with light filters.