Use of a evolutionary algorithm to optimize interplanetary transfers

In this paper, it was studied the optimization of the cost of interplanetary missions with emphasis on reducing fuel consumption. To achieve this goal, a genetic algorithm was implemented to optimize the total impulse of orbital transfer. It was implemented a case of sending a space vehicle from Earth to a another planet using a gravity assist maneuver (swing by), in this paper it was chose sending a spacecraft from Earth to Mars with a close approach to the Venus. The method employed can be used for impulsive interplanetary missions in general, and so the solution found can become an initial solution for numerical methods of optimization of low thrust maneuvers

On the feasibility of developing a single-stage acceleration/deceleration unit based on the oxygen-hydrocarbon engine 11D58M for a super-heavy launch vehicle

The paper presents results of unsolicited exploratory design studies done by the authors into the feasibility of developing for a super-heavy launch vehicle a single-stage oxygen-hydrocarbon acceleration/deceleration unit (ADU) with two liquid-propellant rocket engines 11D58M developed by RSC Energia, intended for insertion of manned spacecraft into lunar orbit, as well as for insertion of super-heavy spacecraft into geostationary orbit (including the orbital module high-apogee transfer profile using lunar gravity assist maneuver). It demonstrates that the single-stage ADU will have a number of important advantages over both a single-stage oxygen-hydrogen ADU and a functionally similar two-stage acceleration/deceleration system of an orbital module in the form of a tandem stack of an oxygen-hydrogen acceleration stage and correction and braking stage. To assure the start-ups of the main liquid propulsion system of the ADU, it proposes a new method for inertial propellant component phase separation in the tanks in zero-gravity environment using a pre-startup pre-programmed ullage separation turn maneuver of the orbital unit about its transverse axis of inertia. Key words: Integrated launch vehicle, launch vehicle, orbital module, upper stage, orbital transfer vehicle, acceleration/deceleration unit, ullage maneuver, liquid-propellant rocket engine.

Gravity-assist maneuvers in implementation of Martian manned expedition with an electric rocket propulsion

The paper focuses on the analysis of energy-ballistic efficiency of gravity-assist maneuvers in the implementation of the Martian manned expedition in the period 2049–2050. The purpose of this analysis was to identify the opportunities for improving the energy-ballistic performance indicators of the Martian manned expedition through gravity-assist maneuvers around the Earth and Venus. The methodical approach to calculating the main energy-ballistic indicators of the Martian manned expedition is based on dividing the flight trajectory into sections. To determine the main characteristics of these sections, the statement corresponding to the restricted two-body problem was used. The heliocentric trajectory sections were optimized using the Pontryagin maximum principle. The families of solutions with a gravity-assist maneuver near Venus were obtained, differing in the direction of the flyby of Venus and the height of the flight orbit pericenter. The research shows the existence of extremals close in characteristics, which are with the fly-by orbit pericenter altitude restriction and without it. A comparison was made in terms of the duration of the expedition and the initial mass with solutions without a gravity-assist maneuver.

Synthesizing spacecraft orbits with high inclinations using Venusian gravity assists

An adaptive, semi‑analytical, and geometrically clear method for synthesis of sequences of Venusian gravity‑assist maneuvers setting the desired inclination of a spacecraft orbit is proposed. The geometric constraint on the maximum possible inclination of a spacecraft orbit, which depends on the asymptotic spacecraft velocity relative to Venus, and the dynamic constraint (arising when a gravity‑assist maneuver is performed) on the angle of rotation of the vector of asymptotic velocity relative to Venus are considered simultaneously.

Chaotic Dynamics in a Low-Energy Transfer Strategy to the Equilateral Equilibrium Points in the Earth–Moon System

In the frame of the equilateral equilibrium points exploration, numerous future space missions will require maximization of payload mass, simultaneously achieving reasonable transfer times. To fulfill this request, low-energy non-Keplerian orbits could be used to reach L4 and L5 in the Earth–Moon system instead of high energetic transfers. Previous studies have shown that chaos in physical systems like the restricted three-body Earth–Moon-particle problem can be used to direct a chaotic trajectory to a target that has been previously considered. In this work, we propose to transfer a spacecraft from a circular Earth Orbit in the chaotic region to the equilateral equilibrium points L4 and L5 in the Earth–Moon system, exploiting the chaotic region that connects the Earth with the Moon and changing the trajectory of the spacecraft (relative to the Earth) by using a gravity assist maneuver with the Moon. Choosing a sequence of small perturbations, the time of flight is reduced and the spacecraft is guided to a proper trajectory so that it uses the Moon's gravitational force to finally arrive at a desired target. In this study, the desired target will be an orbit about the Lagrangian equilibrium points L4 or L5. This strategy is not only more efficient with respect to thrust requirement, but also its time transfer is comparable to other known transfer techniques based on time optimization.