Introduction to Interplanetary Travel <br/>— Pocket Edition

The main part of space travel within our Solar system consists of following an orbit determined, to a good approximation, by Sun’s gravity only. In this article, we introduce a new technique for dealing with the resulting Keplerian motion, both elliptical and hyperbolic. This new method provides a simple way to establish parameters of the ensuing trajectory and compute the location and velocity of a spacecraft at any future time. Another essential feature of such travel, when visiting several planets in a single mission, is the utilization of each planet’s gravity to increase and re-direct a spacecraft’s velocity to enable it to reach the next, more distant planet. We derive and demonstrate all the relevant formulas required to understand the basic principles of designing such an interplanetary journey.