KUKAI is a pico-satellite developed by Kagawa University and was launched by the H-IIA rocket by the Japan Aerospace Exploration Agency (JAXA) on 23 January 2009. The primary objective of KUKAI is technical verification of a tethered space robot, which is a new type of space robot system proposed in previous work. KUKAI consists of mother and daughter satellites for tether deployment. This was the first time to launch mother-daughter satellite among pico-satellites less than 10kg in the world. Then, it is important to develop separation mechanism. The separation and the launch lock mechanisms for KUKAI have been developed, and confirmed and evaluated by launch environment and microgravity condition. As the launch result, KUKAI was separated from the rocket as planned, the system started normally, and deployment of the solar paddle and the antenna was succeeded.