Preliminary Study and Experiments on Water Landing of the Japanese ISS Cargo Return Vehicle Using A Ram-Air Parachute

摘要

Thispaper reports the status of a preliminary study and experiments on a water landing of the Japanese ISS cargo return vehicle using a ram-air parachute. Our final target of the study is to use a ram-air parachute for the future human space transportation system as an autonomous precision gliding and soft land landing technology to predetermined conventional landing sites, such as those in the Japanese islands. The purpose of applying the ram-air parachute to the ISS cargo return vehicle is to demonstrate the feasibility and practicability of a ram-air parachute for a reentry vehicle from space. We also demonstrate the water landing capability as a contingency landing scenario of the future human space transportation system. To compare the characteristics of a gliding water landing by a ram-air parachute with a nongliding vertical landing, some cases of water landing tests using a miniature model of a ram-air parachute and a capsule were conducted. Using the results of the tests, we confirmed the effects of impact attenuation by gliding landings. In addition, we found that an optimization of a water landing approach using flare control is important to minimize the impact loads during water landings.