ESA GNC Conference Papers Repository

For new space transport missions such as orbital recovery from Low Earth Orbit (LEO) and the rocket first stage recovery, accurate reentry guidance has become increasingly important. JAXA realized two orbital recovery missions, Orbital Reentry Experiment (OREX) and HTV Small Re-entry Capsule (HSRC). The recovery accuracy of OREX is about 100km and those of HSRC is about 10km. However practical capsule recovery system will need about 1km accuracy to land on Japan mainland. In this paper shows the way to realize 1km reentry guidance accuracy, on-orbit alignment, IMU-Drag Measurement-GNSS navigation, real-time integration guidance. guidance using wind information. JAXA also has been studying rocket first stage recovery mission which uses reentry guidance using aerodynamics force until the final engine burn start. Issues of the reentry guidance of rocket first stage recovery are different from those of orbital recovery. The issues are followings. (1)Short time of reentry guidance using aerodynamic force. (2)High dynamics pressure of re-entry flight. (3)How to combine aerodynamics reentry guidance and guidance using propulsion. Since using aerodynamic reentry guidance might reduce the fuel consumption of rocket first state recovery, we have been investigating on reentry guidance for rocket first state recovery mission. This paper shows the difference between re-entry guidance for orbital recovery and those for rocket first state recovery. This paper also describes the issues of the reentry guidance for rocket first state recovery.