At the beginning of the career you have the "Explore" task, which simply means visit the place. This can be done with the lander, which has a limited amount of fuel.

So if you automatically visit the place everything is perfect. But as soon as you enter the emergency mode (one or more fuel chambers low) you can't complete the mission, even if you land it exactly where it should be.
This renders the lander useless, sometimes after one mission. {F33181}