[XorNot]

Having enough lift capacity to take a shot at putting a pair of telescopes out far enough to exploit solar gravitational lensing to resolve exo-planet surfaces would be a hell of a thing. Orbital refueling would mean we could reasonably build something big enough to be able to boost out that far (would still take decades to arrive).

[cryptonector]

Isn't that 500 AU out?

[XorNot]

Yes, but the trick with getting there is building the vehicle. Time takes care of the rest (you'd do it using ion thrusters).