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Kibo Structure -Airlock-

An airlock is a passage or a small room that enables people or goods to pass between places differing in pressure by adjusting to the pressure difference between them. Below, we will first give an overview of an airlock then introduce Kibo's airlock.

1. What is an Airlock?
If there is only one door between locations of unequal pressures, a strong air will be generated from the higher pressure side to the lower side when that door is opened. In order to avoid this phenomena, two doors are between the locations with unequal pressures. People or goods enter one door. That door is then closed, and the pressure between the doors is adjusted to the pressure of the destination. This is an airlock.
An example is Space Shuttle's airlock. When extravehicular activities (EVA) are conducted, astronauts exit the Space Shuttle through its airlock. In the future an airlock will be attached to the International Space Station, which is now being constructed, and crew members will exit the ISS to conduct EVAs.
Click here to view airlock operation procedures for EVA.

2. Kibo's Airlock
Small window on the inner hatch
Kibo's airlock is dedicated to goods and cannot accommodate people. The maximum size of an item that can pass through this airlock is 576x830x800 mm. The airlock attached to the Kibo's Pressurized Module (PM) will be utilized when experiment equipment or materials need to be transferred between the PM pressurized to one Earth atmosphere and the Exposed Facility (EF) located in the space vacuum.
As shown in the figure below, the airlock is cylindrical and is attached to the pressurized module's manipulator side. One cylinder hatch is located on each side. The hatch on the PM side is called the inner hatch; the hatch exposed to space is called the outer hatch. Items to be transferred through the airlock are first fastened on a slide table then transfered by sliding this table. The inner hatch has a small window that enables viewing the inside of the airlock.

Airlock location

Kibo's airlock

Outer hatch Inner hatch Slide table

3. Using the airlock
Kibo's airlock operation is explaned below using the example of moving items from the PM to the EF. First, turn on the power and open the inner hatch. Extend the slide table into the Pressurized Module, fasten the items to it, move the table back into the airlock, and close the inner hatch. Evacuate the airlock using a vacuum pump, then open the outer hatch. Extend the slide table to the Exposed Facility side, pick up the items by the remote manipulator, and put the items on the EF. Slide the table back into the airlock and close the outer hatch. Return the air to the airlock and turn off the power.

The figures below show the procedure stated above.


Turn on the power.

Open the inner hatch. Extend the slide table into the PM.

Fasten the items such as an ORU to the slide table.

Move the slide table back into the airlock and close the inner hatch.

Evacuate the airlock

Open the outer hatch and extend the slide table.

Pick up and transfer the items by the remote manipulator.

Slide the table back into the airlock and close the outer hatch.

Return the air to the airlock.

Turn off the power.
* ORU iOrbital Replacement Unit) :
General name for items that are replaceable in orbit such as spacecraft components or experiment equipment.

4. Dimension of Kibo's airlock
EF section diameter : 1724mm
PM section diameter : 1410mm
Length : 2001mm
Size of items
approx 576X830X800mm
Peak : less than 600w

5. Kibo's development test status
Functional tests of the slide table and the hatches were conducted on August 4 and 5, 1999.
The test report is presented here.

Last Updated : February 9, 2000

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