HOUSTON—Astronauts debuted the international space station’s newest piece of equipment Saturday during a successful but very limited test.

Space shuttle Discovery crew members Akihiko Hoshide and Karen Nyberg moved two of the six joints on the Japanese Kibo lab’s robotic arm for the first time, maneuvering them very slightly with a series of commands.

“The very first maneuver was completed successfully,” Hoshide told Japanese flight controllers near Tokyo.

Full deployment of the 33-foot arm will be done after Discovery leaves the station next week. However, it won’t be used for any actual work until after the launch into orbit next year of the billion-dollar lab’s third and final section — a “porch” for exterior experiments — and a second, smaller robotic arm.

After he and Nyberg finished testing the robotic arm, Hoshide reflected on what Kibo means for Japan.

“It’s a big milestone. We have our own house here now,” Hoshide said during a series of media interviews Saturday.