Abstract
The Unmanned Space Experiment Recovery System （USERS） has been established as the Unmanned Space Experiment Infrastructure with long duration and better micro‐gravity environmrnt capability by the successful return of the first USERS Spacecraft return capsule called REV on May 30, 2003. In this paper, after brief introduction of the first USERS Project and the merit of the Unmanned Space Experiment System, the analysis and the clarification results of what have been established and what have to be prepared as addition of options, such as to have late and early access capabilities, to the first USERS flight to be a fully operational unmanned experiment infrastructure, will be described. The brief schematics of this improved and generalized USERS for wide range of the users demands will follow, and finally, the Utilization Guide of the USERS, which has been prepared for wide range of users, will be introduced.
