Kirobo – derived from the Japanese words for “hope” and “robot” – was among five tons of supplies and machinery on a rocket launched for the International Space Station from Tanegashima, south-western Japan.
Developers say the childlike robot will be a companion for astronaut Koichi Wakata and will communicate with another robot on Earth.
Robot designer Tomotaka Takahashi, of the University of Tokyo, advertiser Dentsu and car maker Toyota worked on the robot.
The challenge was making sure it could move and talk where there was no gravity.
Ahead of the launch, the 34cm (13in) Kirobo told reporters: “One small step for me, a giant leap for robots.”