Analysis of Rocket Modelling Accuracy and Capsule Landing Safety

Abstract

The capability of performing vertical landing accurately and safely is of great concern for reusable rockets, some of which might carry manned capsules. According to previous technologies, the rocket needs to accurately land on a drone ship that has a limited size of 70 m × 50 m, whereas the capsule needs to safely land on a soil terrain that might be oblique. Currently, there has been various research supporting the landing processes of rockets and capsules. Regardless of the disparity of such research, the accuracy and safety are the essential indicators to be considered. This paper develops a more accurate landing model for rockets by reviewing valid methodologies for error mitigation. The position error of the rocket (13.46 m) is smaller than the radius of the terminal dock of the drone ship (25 m); thus, the modelling accuracy of the rocket is within its accuracy requirement (with a 95% probability). After the performance in terms of accuracy is quantified, a novel landing gear is designed to deal with sloped terrains, which might have a negative effect on landing safety. The struts of the novel landing gear include actuators, buffer struts, and a scanning system. This scanning system is used to extract sloped terrain information, and then the actuators are used for the adjustment of different landing struts, ensuring that these struts touch the sloped terrain at the same time. Compared with conventional landing struts, the novel landing gear is used to increase the buffer efficiencies of the buffer struts.