problem solving again!?

Question

The Rocket Ship
A rocket ship is to go from Earth to Planet X. It is a five-day trip, but the rocket holds only enough fuel for 3 days’ flight. Fuel stations 1, 2, and 3 are 1, 2, and 3 days’ flight from Earth respectively. The fuel stations are empty, but Earth has an unlimited supply of fuel. The rocket ship can leave fuel at stations 1, 2, and 3. What is the minimum number of days required to reach Planet X from Earth?

Answer 1

Now I know why we humans haven't left earth yet and spread throughout the galaxy.
We haven't even been able to get to planet X yet.