Re: Landing robots
It's velocity that matters, much more than distance. If you want to land on this thing, you've got to match velocities with it. Which means carrying all that fuel and engine mass anyway.
Most of the probes we send out get up to speed in a relatively short burn to achieve Earth escape velocity, plus a bit - then coast for a few years to get to their target with most of their instruments turned off. In the case of a nearby object you don't need the coast phase, but you still need the velocity.
Well I suppose it does depend on your definition of "landing". How soft do you want your probe's impact to be? Instrument-survivable, or will 50,000kph do?