<p>JAXA and some universities have proposed a hypersonic flight experiment named “HIMICO: High Mach Integrated Control Experiment” using a 1.5-meter class vehicle launched by the S-520 sounding rocket. The experiment aims to establish an integrated control method including the interference between the airframe and engine under the actual Mach 5 flight condition. Two flight experiments are planned step by step to reduce technical risks. Feasibility studies have been conducted by experiments and CFD analysis. This paper reports the summary of the flight test plan and preliminary studies on the vehicle shape, flight trajectory, component design and technical issues.</p>