Abstract
Recently, the suborbital plane has attracted attention for space tourism. However, the suborbital plane has some aerodynamic problems such as severe aerodynamic heating and deceleration G from aerodynamic forces. To solve these problems, a high-drag-force device, like a parachute, is thought to be effective, since high-drag-coefficient spacecraft can reduce the velocity at an early stage of atmospheric re-entry to the Earth. In this study, we investigated experimentally the aerodynamic characteristics of the parachute for the suborbital plane as the high-drag-force device by using three kinds of model in a hypersonic wind tunnel. From this experiment, the following results were obtained: 1) the drag force increases drastically when a parachute is used, 2) the effect of increasing drag force depends on the strength of the shockwave which is generated from the suborbital plane, 3) the shape of the parachute shows a periodic pattern, and 4) the parachute may have more than two mechanically stable shapes. These results suggest that the hypersonic parachute system is useful as a high-drag device for suborbital planes from the viewpoint of increasing drag coefficient.
