5. Lunar Transfers

We have seen that direct transfers to celestial bodies in the sky can fairly easily be calculated using the linked conic approach and a Lambert solver. After this, a transfer to the Moon should look easy. Unfortunately, transfers to the Moon cannot be simplified using the linked conic approach: the Earth is too close by and its gravity, even when arriving to the Moon, is still present. Therefore there will be two main gravity forces acting on the satellite, and we cannot always ignore the presence of the Sun’s gravity. A linked conic approach, which assumes that there is only one main gravity force, does not apply here. In this chapter we will look at different ways to get the Moon. In order to understand how to get there though, we first need to understand what are the characteristics of the Moon.