The Air Lock (エアロック, Ea Rokku) is a room found at the start of Metroid Prime, the Frigate Orpheon. It is a small room connecting the exterior landing dock of the frigate to its interior. When it is entered, Samus must scan a panel to pressurize the room in order to proceed to further rooms. Later, while escaping during the reactor meltdown, the room depressurizes before the outer door becomes usable. When the frigate crashes on planet Tallon IV, this room is destroyed along with many other rooms.
Dead Parasites can be seen floating in the Air Lock, along with other debris. They can be shot and destroyed, but not scanned. Pressurizing the Air Lock causes these objects to fall, indicating that the room and all others inside the frigate have an artificial gravitational field in place.
- "Door cannot be opened until air lock is repressurized. Use the activation panel to repressurize room."
- "Air lock repressurization successful."
- Air locks are common plot elements in the Alien franchise, a series on which Metroid was based. Often, the main character Ripley would ultimately flush a stowaway Alien out an air lock in the climax of a film.
- Somehow, Samus does not seem to be affected by the lack of gravity in the room unlike the rubble and the parasites.
- In Metroid: Other M, there is a room in the Biosphere which has a similar premise to the Air Lock. In this hallway, the door is locked, and when a Sensor is shot, the room is repressurized and the door unlocks.
- When the player enters the airlock for the first time, and the room pressurizes, the player can still turn around and walk right back out to the depressurized areas.