Technical Challenges and Study on Guided Reentry Flight for Capsule Spacecraft

摘要

Previously-realized Japanese capsule spacecraft, OREX (Orbital Re-entry Experiment), USERS capsule, and HAYABUSA reentry capsule, were all ballistic reentry capsules, which flew without any guidance during reentry and had large splashdown areas. To establish practical recovery systems from the International Space Station (ISS), JAXA has been studying reentry capsules using guided reentry flight, which enable capsules to narrow their splashdown area within 5 km and reduce aerodynamic acceleration less than 4 G. To improve reentry guidance accuracy, we use accurate real-time prediction guidance using numerical integration for reentry spacecraft and IMU-GPS-ST integration navigation. This paper describes the characteristics of guided reentry flight and technical challenges on guided reentry flight for capsule spacecraft and presents guidance and control methods of guided reentry flight for the technical challenges.