The space transportation system using capsule/rocket configurations such as Apollo and Soyuz are simple compared with Space Shuttle, and have several merits from the viewpoint of reliability. The capsule/rocket system will take over the Space Shuttle, after it retires in 2010. As the Space Shuttle accidents had been caused by several factors, e.g., aerodynamic interaction of shock waves ahead of its wing, advanced abort systems such as LAS (Launch Abort System) are required for the capsule/rocket system. In the present study, as a baseline configuration, a combination of a cone and a cylinder is employed as a CEV (Crew Exploration Vehicle), which consists of a capsule (LAV: Launch Abort Vehicle) and a rocket (SM: Service Module). By changing the relative position of the two components as well as the profile area of the rocket, their effects on the capsule/rocket aerodynamic interaction and characteristics (drag and pitching moment) are experimentally and numerically investigated at a supersonic speed (
M∞ = 3.0). It is found from the results that the clearance have little effects on the flow field for the case of the baseline configuration. The capsule always showed a positive drag (
CD = 0.34), which means that thrust is required to overcome the drag. Otherwise the capsule will recontact the rocket. However in the case where the rocket contact area is 2.2 times as large as the capsule profile, more favorable effects were obtained. Especially in the case of a certain clearance (
h/
D = 0.40), the drag coefficient of the capsule is
CD = −0.35, which means that the capsule suffers a thrust force from the aerodynamic interaction. Under this condition, if capsule has a pitch angle with 5 degrees instantaneously, then pitching moment coefficient becomes
CMp = −0.41 therefore capsule stabilize. However, in the case of a very small clearance (
h/
D ∝ 0.00), the flow becomes unsteady involving pulsating shock wave, leading to a potentially risky separation of the capsule.
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