119 Optimizing asymmetric cislunar transfers & back using hybrid propulsion

Job title:

119 Optimizing asymmetric cislunar transfers & back using hybrid propulsion

Company:

Centre National d’Etudes Spatiales

Job description

25-119 Optimizing asymmetric cislunar transfers & back using hybrid propulsionPostuler25-119 Optimizing asymmetric cislunar transfers & back using hybrid propulsion

• Doctorat, 36 mois
• Temps plein
• Indifférent
• Maitrise, IEP, IUP, Bac+4
• Flight dynamics

PostulerMissionLunar Sustainable exploration, aiming at crew return, permanent infrastructures in the next decade will require an effective transport and logistic infrastructure between Earth and Lunar Orbit: Cislunar to the Lunar Gateway, Low Lunar Orbit for landers. This exploration is paving the way to future Mars exploration, which may also use a Cislunar Spaceport (the Lunar Gateway or its evolution). This PhD research aims to optimize asymmetric Earth-to-Moon transfers, where the outbound and return trajectories differ, through a co-optimization process involving both trajectory and system design. By integrating hybrid propulsion systems, the study seeks to improve the efficiency and robustness of the entire mission, from launch injection to rendezvous with the lunar station and return to Earth until the re-entry. Emphasis is placed on reducing fuel consumption by taking advantage of low-energy transfer techniques, such as weak stability limit (WSB) dynamics, and other innovative strategies, as well as on the study of uncertainties. The research targets fuel-efficient, resilient solutions for both the outbound and return legs, ensuring a robust Earth-Moon-Earth mission cycle.This research focuses on the optimization of Earth-Moon trajectories and return trajectories using different strategies taking advantage of the natural dynamics of the Earth-Moon-Sun problem and resonant orbit transfers such as the weak stability limit (WSB). WSB dynamics help identify low-energy pathways, reducing fuel requirements by using gravitational assists from the Earth, Moon, and Sun. The re-entry strategies focus on optimal approach angles and aerocapture techniques for a safe return to Earth.This study introduces the innovative use of hybrid propulsion systems, combining impulsive (high-thrust) and low-thrust propulsion for fuel-efficient lunar missions. The goal is to develop an algorithm that co-optimizes both the spacecraft’s trajectory and propulsion parameters, drawing on techniques like Composite Smoothing Control (CSC) for efficient mission planning. This co-optimization process enables multi-criteria (DV, time of flight, power, mass, Isp,..) optimization to maximize payload mass while taking into account the launcher’s capabilities. In addition, previous research on trajectory optimization highlights the value of combining global (evolutionary) and local optimization methods to obtain efficient solutions in complex multi-body environments. This combination results in robust and optimal solutions that take into account operational constraints, minimizing fuel consumption while ensuring that the spacecraft meets the phasing conditions for rendezvous with the lunar gateway within a narrow time window.The third part of this PhD will focus on the management of uncertainties.These uncertainties can arise from factors such as variations in propulsion performance, spacecraft mass and environmental conditions. The research will aim to develop strategies that guarantee mission robustness despite these unpredictable variables. This will help optimize trajectory design and improve the reliability of mission results.In conclusion, this PhD research aims to advance orbital mechanics by developing a comprehensive optimization framework for asymmetrical Earth-to-Moon transfers. By integrating various strategies such as WSB theory, developing hybrid propulsion co-optimization techniques and studying transfer uncertainties, the research aims to generate reliable, robust and low-consumption trajectories. The results will have a significant impact on the design of future space missions, facilitating cost-effective and reliable transfers between Earth, the Moon and beyond.For more Information about the topics and the co-financial partner (found by the lab !);contact Directeur de thèse –Then, prepare a resume, a recent transcript and a reference letter from your M2 supervisor/ engineering school director and you will be ready to apply online before March 14th, 2025 Midnight Paris time !ProfilAerospace engineer with strong knowledge in space mechanics & astrodynamics

Expected salary

Location

Toulouse

Job date

Wed, 05 Feb 2025 05:59:41 GMT

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