Working together with NASA astronaut Timothy Creamer, the 44-year-old Noguchi opened the air lock for the first time, brought out the 2.2 meter-long arm into space and attached it at the tip of a longer, 10- meter arm.
The installation of the smaller arm is aimed at allowing astronauts to engage in more delicate operations, including fixing problems with experimental devices, from inside the space station.
The agency, known as JAXA, plans to undertake checks until Friday to confirm if the newly installed arm is moving properly.