We know, that to travel to another star systems, we need to use FTL for traveling. But if you need to travel to another planet in the same star system, what type of travel should be used? Is it worth using fuel costing engines like warp drive (because it uses "exotic matter", a lot of it)?
An energy efficient method would be to use solar sailing or to convert solar energy to one of the different electro propulsion engines. All technologies are either used or existant, but not efficient enough yet and depend on the so far most reliable resource you can "obtain" in a solar system, which is a sun. Those methods also have the potencial to reach high velocity over a relatively small amount of time.
Is (comparatively) short-range teleportation like the transporters in Star Trek an option? Perhaps there could be wormhole-like gates similar to those in Stargate.
If we’re looking for “super fast” instead of instantaneous, I am imagining something along the lines of a railgun or maglev launcher that propels vehicles based on a trajectory calculated to put them in some sort of deceleration field or other object that uses magnetics to influence trajectory or momentum in the orbit of the destination planet. I imagine the lack of friction makes maintaining momentum easy to the point of not burning fuel once sufficiently launched.