It is only in fairly recent years that the idea of sending an object to another planet has become a practical reality. This has led to the rapid development of celestial mechanics, although the subject is by no means new. The purpose of the paper is to introduce the subject and to see how well-established results and equations may be utilised to find out about the motion of an object on its way to another planet. Once the path is determined, various deductions may be made about the rocket vehicle which must place the object or spacecraft along that path.

The concept at “launch window” will be introduced and a method of determining it will be presented. Once it is known, the number of available trajectories (although theoretically infinite) are narrowed down by selecting desired values of some parameters.