Gaia is a planned European Space Agency's (ESA) space observatory that will aim to chart a three-dimensional map of our Galaxy, the Milky Way. It is planned to operate around the Sun–Earth $L_2$ (SEL2) Lagrangian point. What is the flight plan to get Gaia in orbit around SEL2? We can break this down into a few sub-questions:
- How many Earth flybys are planned?
- Will the Moon be used as gravity assist?
- Does it need lots of fuel to slow down near L2?