A re-entry trajectory design method with short voyage and low overload

Abstract

The invention discloses a short-range and low-overload reentry trajectory design method, which considers introducing the concept of a gliding type reentry of a spacecraft with a large lift-to-drag ratio for the reentry process of an aircraft that reenters the atmosphere at a speed close to the second cosmic speed. First, set the flight at a constant roll angle in the initial descent section, and introduce trajectory parameters in the gliding section and the end to describe the trajectory; then according to the relationship between the trajectory parameters and the control command roll angle, the required control command is obtained; in order to achieve low overload, the introduction of overload Limit, when the overload exceeds a certain range, reduce the roll angle appropriately to ensure that the overload does not exceed the maximum limit requirements; finally, by correcting the roll angle of the initial descent section, the requirements of different voyage tasks are realized.

Description

technical field [0001] The invention relates to trajectory planning technology, which belongs to the field of aircraft re-entry guidance, and can be applied to the guidance strategy of a re-entry spacecraft with a small lift-to-drag ratio during re-entry into the atmosphere. It has certain reference value for the emergency return process of the existing manned spacecraft. Background technique [0002] The lunar probe returner re-enters the atmosphere at the second cosmic speed and faces severe thermal constraints. For the manned returner, the corresponding overload constraints and landing point accuracy requirements are higher. The existing reentry methods of the earth's atmosphere mainly include ballistic reentry, ballistic-lift reentry, and lift reentry. For the manned lunar exploration return vehicle, the return process is mainly realized by the jumping reentry method in the ballistic-lift type. Under the action of the lift force, it rushes out of the atmosphere again, a...

AI Technical Summary

Problems solved by technology

By jumping re-entry, the designable voyage range of the spacecraft re-entry can be widened, and the maximum re-entry overload and heat flow can be reduced. However, for emergencies that require rapid return with a short voyage, the re-entry time is long and the total heat absorption is large. The problem

Although the existing emergency return method of ballistic reentry is relatively simple, there is a problem that the reentry overload is relatively large, which may reach 7-13g, and the landing points of the return capsule are scattered widely.

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