Seminars

Lecturer: Prof. Moshe Guelman (Technion)
Date: 2007-05-25 10:00
Place: Aniara

Solar Electric Propulsion for Low Earth Orbit Transfer

Prof. Moshe Guelman
The Lottie & Max Dresher Chair
Head of Faculty of Aerospace Engineering
Norman & Helen Asher Space Research Institute
Technion, Israel Institute of Technology

Electric thrusters have specific impulses from five to ten times that available from chemical thrusters, thus drastically reducing the propellant requirements for a given mission. During the last decade many new concepts were advanced on possible uses of electric propulsion for a variety of missions, such as orbit transfer, formation flying, interplanetary flight, and many others. Use of electric propulsion for low Earth orbit transfer has many specific characteristics. In a LEO mission, the thrust-to-weight ratio is many times smaller than in interplanetary missions. This implies long durations of the maneuvers, counting many hundreds of revolutions. A model of unperturbed motion must include all forces, creating accelerations in the order of the control thrust. Periodic eclipses greatly complicate the thrust program. Work performed on Low Earth Orbit transfer using solar electric propulsion systems will be presented. In this work optimal thrust solutions were obtained for the case in which an eclipse shadow arc restricts thrusting in sunlight only, so that thrusting is intermittent during each orbit. Motivation for this work is the implementation of the joint Israeli-French Venus scientific-technological mission currently under development. Results of both the optimal thrust solution and the actual guidance system proposed to the Venus mission will be presented.


Created 2007-05-02 13:03:48 by Mats Holmström
Last changed 2007-05-08 10:42:22 by Mats Holmström