Extravehicular Activity simulation performed by astronauts

Tsukuba Space Center,Weightless Environment Test Building(WET)

On Jan. 21, 1997, a microgravity simulation test simulating Extravehicular Activity (EVA) in space was started utilizing the Weightless Environment Test Building in Tsukuba Space Center. This test was intended to evaluate whether the Japanese Experiment Module (Kibo), which is going to be attached to ISS in 2002, was designed to allow easy repair and maintenance activities.

Activity in neutral buoyancy environment	Kibo mockup (EF and some portion of PM)

Unlike previously developed unmanned satellites, Kibo is a manned space laboratory which will be operated for over ten years. Maintenance on orbit will be conducted by astronauts. Devices outside Kibo might require maintenance activities in a vacuum and microgravity environment by astronauts in an Extravehicular Mobility Unit (EMU). Kibo must be designed to accommodate such EVA maintenance activities by astronauts. This test evaluates the design of Kibo to determine whether astronauts will have to take difficult positions and whether they can reach the devices to be repaired or maintained.

Slide into water on an elevator.	Donning a space suit.

This is the third test following similar tests held in the US and is the first to have a NASA astronaut participate. Astronaut Wakata and astronaut Jerry L. Ross participated in the test until the end of January. On Jan. 21, both astronauts donned EVA suits and simulated maintenance tasks using the Kibo mockup located in a large water pool.

The two astronauts first adjust the buoyancy of their suit to achieve neutral buoyancy in the water pool by balancing gravity and buoyancy. They then move to the site near the Kibo mockup to conduct evaluation activities following prescheduled procedures. The tests this day simulated various activities such as translation along the outside of Kibo using hand-rails or repairing the robot arm.

Device exchange simulation

After astronauts Wakata and Ross completed their two weeks of testing, another group of two astronauts came to Japan and repeated similar test. Three groups of two astronauts each, including Wakata and Ross, are scheduled to visit Japan and conduct tests until the end of February. Identical tests are being performed by six astronauts to ensure that Kibo was designed so that any size of astronaut can easily conduct maintenance by EVA. When these tests are finished and Kibo's design has been proven to have no problem, flight model production will be started.

Artist's illustration of Kibo

The microgravity simulation tests are not only useful for designing Kibo but they also play an important role in training Japanese astronauts. All of the tests repeated here will mark major milestones towards ISS program completion in the 21st century.

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