This proposal will describe an innovative approach for space flight experiments to demonstrate and validate control-structures inter- action (CSI) technologies and methodologies based on emerging small satellite initiative. This Phase I proposal addresses the concept design for a control-structures interaction satellite (CSI-sat), launching platform and ground mission operations center necessary for performing affordable on-orbit testing of selected CSI technologies which can not be accommodated in ground tests. The advantages of this CSI-sat flight experiment approach are theat (1) it would be a dedicated CSI flight experiment with approximately a one year life time; (2) with the appropriate concept design, numerous guest investigators could flight test innovative materials or components as well as uplink experimental system identification and control algorithms for evaluation; (3) it will provide a reconfigurable platform for flight testing new CSI technologies/methodologies before applying them to operational systems; (4) this approach is potentially 5 to 10 times lower in cost than previously proposed methods.