KUKAI was successfully launched on January 23, 2009 by the H-IIA rocket of JAXA (Japan Aerospace Exploration Agency) with the main satellite “GOSAT.”The planned orbit is sun synchronous (Altitude: 666km, Inclination: 98deg). Main characteristics of KUKAI are: (i) it is two satellites system, mother and daughter; (ii) it becomes a 5m tethered system on orbit at the maximum; (iii) the daughter satellite is a tethered space robot, whose attitude can be controlled by its own arm link motion. The mother satellite has tether deployment and tension control systems, and it deploys the daughter satellite and retrieves it. The daughter satellite is a tethered space robot, and it has one arm link attached to the end of the tether.After the separation from the rocket, the initial check for satellite condition was confirmed successfully for the first 10 days.Though tether deployment mission was performed after the initial check, tether was deployed for several centimeters only due to the launch lock trouble of the tether reel mechanism. However, basic functions of the tether reel and the robot mechanisms were confirmed.