Airlock

STS-125 EVA3a

SEAL Delivery Vehicle Team (SDV) 2

STS-103 closing the airlock

Airlock is a device that permits the passage of people and objects between a pressure-controlled environment and another area without the disruption of the environmental conditions of either. Airlocks are critical in various fields, including space exploration, scuba diving, medicine, and biotechnology, where maintaining specific atmospheric conditions is essential.

Function and Types

The primary function of an airlock is to preserve the atmospheric integrity of a controlled environment while allowing for the transfer of personnel and materials. Airlocks can be found in a variety of forms, each designed to match the specific requirements of its application.

Spacecraft and Space Stations

In spacecraft and space stations, airlocks serve as critical components for extravehicular activities (EVAs). They allow astronauts to transition from the pressurized cabin to the vacuum of space and back without compromising the spacecraft's atmosphere. Spacecraft airlocks are equipped with multiple doors that are operated in sequence to prevent the loss of cabin pressure.

Submarines and Diving

For submarines and during scuba diving operations, airlocks help in maintaining the pressure necessary to avoid decompression sickness. Diving bells and submersible vehicles use airlocks to ensure divers can enter and exit without affecting the vessel's internal pressure.

Medical and Research Facilities

In medical and research facilities, especially those dealing with infectious diseases or sensitive biological samples, airlocks prevent the escape of contaminants. They create a barrier between different pressure zones, ensuring that pathogens do not travel from high-risk areas to clean zones.

Industrial Applications

Airlocks are also used in various industrial applications, including pharmaceutical manufacturing and food processing, to prevent contamination and ensure a sterile environment.

Design Considerations

The design of an airlock depends on its intended use, with key considerations including the size, pressure differential, and the type of atmosphere being contained. Airlocks for space missions, for example, must be lightweight yet robust enough to withstand the harsh conditions of space. Conversely, airlocks for underwater use are designed to resist high external pressures.

Operational Procedures

Operating an airlock involves several critical steps to ensure safety and maintain environmental conditions. The process typically includes pre-pressurization, door sealing, and stabilization of pressure between the airlock and the target environment. Safety protocols are paramount, especially in high-risk applications like spacewalks or handling hazardous materials.

Challenges and Developments

The development of airlocks continues to evolve with advancements in technology and materials science. Challenges include improving reliability, reducing weight, and enhancing safety features. Future developments may focus on automated systems for more efficient operation and integration with other environmental control systems.