Designing the low-energy lunar transfers trajectories which pass in the vicinity of the libration points of the Earth - Moon system. Part 2. Algorithm and numerical analysis

Abstract

An algorithm for designing a low-energy lunar flight trajectory is presented. It is based on the assumption that low-energy flight trajectories pass through the vicinity of one of the collinear libration points of the Earth - Moon system (L1 or L2). It is also assumed that at the moment of spacecraft flight in the vicinity of the libration point, the elements of the osculating geocentric orbit of the spacecraft are close to the elements of the osculating geocentric orbit of the libration point itself. The results of a numerical analysis of the obtained low-energy lunar flight trajectory are presented. It is shown that the use of such a trajectory makes it possible to reduce the deceleration impulse of the velocity during the transition to a low lunar orbit to a value of 638 m/s (in the traditional flight scheme, this impulse turns out to be more than 800 m/s). The influence of solar gravitational disturbances on the flight trajectory is analyzed. It is demonstrated that these perturbations ensure the approach of the spacecraft to the Moon with a negative selenocentric energy constant and contribute to the temporary capture of the spacecraft by the Moon. The influence of the terrestrial gravitational perturbation on the circumlunar part of the trajectory is studied. It is displayed that on the trajectory found this perturbation effectively reduces the selenocentric velocity of the spacecraft. The conditions for spacecraft flight in the vicinity of the libration point are considered.

Keywords

• low-energy trajectory
• flight trajectory
• gravitational perturbations
• velocity impulse