Lunar Orbiter Trade Study and Conceptual Design of Onboard Propulsion System

Abstract

In recent years, the lunar explorer programs, suspended for a long time, have resumed again with the rapid development of low-cost, high-level technologies, and hence several nations have made a success of lunar exploration programs with their own developed orbiters. Late in 2007, the Science Ministry of the Republic of Korea announced that Korea planned to send its first orbiter to the moon by the year 2020. The major objective of the present study is to set up a fundamental baseline on which to design an optimal type of onboard propulsion system. To do this, the mission requirements of the Korean lunar orbiter are summarized at first. Next, the mission requirements of various orbiters are surveyed and also an overview of their key design specifications is investigated. Based on the results of this trade study, the conceptual design of the onboard propulsion system of the Korean lunar orbiter is finally discussed with its major key design requirements of the expected propellant quantity, the minimum thrust level for lunar orbit insertion, and the specific characteristics of the necessary components along a whole system schematic diagram.Nomenclature g = gravity acceleration, m=s 2 I sp = specific impulse, sec M fuel = fuel mass, kg M wet = wet mass of the orbiter, kg V = delta-V, m=s

Overview of Earth-Moon Transfer Trajectory Modeling and Design

“…4) were further developed for other available propulsion systems, like an electric propellant or a solar sail, significantly enhancing the payload capability and enabling high V missions. The primary transfer approach to the Moon can be broadly classified into four categories: direct transfer, phasing loop transfer (also known as direct, staging), low-energy transfer, and spiral transfer [1]. The direct Moon transfer trajectory is the most commonly used method in engineering tasks [2].…”

Study on maintaining formations during satellite formation flying based on SDRE and LQR

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Abstract: Due to the in uence of various perturbations of space, satellites ying in formation cannot maintain speci c con gurations for long durations [1,2]. In order to ensure that formation con gurations are able to meet the requirements of space missions, it is important to maintain control of formation con gurations.

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