You could build and launch probes at regular intervals to L4 and L5, and dispatch them from there via low-energy transfer.
It would take months for each probe to get there, but once one arrives, you can transfer it from there to anywhere else in the universe far more easily than from the Earth's surface. And since those points are more stable than L1, L2, and L3, you can just leave the probe there for months or years until a good transfer opportunity comes up.
It would take months for each probe to get there, but once one arrives, you can transfer it from there to anywhere else in the universe far more easily than from the Earth's surface. And since those points are more stable than L1, L2, and L3, you can just leave the probe there for months or years until a good transfer opportunity comes up.