93-177

Jupiter Swing-By Trajectories Passing Near The Earth

Roger A. Broucke* and Antonio F. B. A. Prado**

Abstract

We study and classify the Swing-By maneuvers that use the planet Jupiter as the bodv for the close approach. Our goal is to simulate a large variety of initial conditions for these orbits and classify them according to the effects caused by the close approach in the orbit of the spacecraft. We use the well-known regularized (Lamaitre regularization) planar-restricted-circular-threebody problem as our model. We especially check which ones of those orbits have a passage near the Earth. This is very important. because only those orbits have a potenual use for transfers from the Earth. We show our results in letter-plots, where one letter descnbing the effects of the Swing-By is plotted in a two-dimensional graph that has in the honzontal axis the angle ~ (the angle between the pengee vector and the Sun-Juplter line) and in the vertical axis the lacobian constant of the spacecraft. We make one plot for each value of the pengee distance (the distance between the spacecraft and Jupiter during the close encounter).
*Department of Aerospace Engineering and Engineering Mechanics, University of Texas, Austin, Texas 78712.

**University of Texas at Austin and Instituto Nacional de Pesquisas Espaciais (INPE-Brazil).