One word : One word teleprescense

Imagine a remotely controlled robot that is so well constructed that it can do anything that a person can do, except think.

Imagine that you attach sensors, actuators and other types of ors to your body such that as far as your senses are concerned you ARE the robot when you activate them.

Imagine all of the pros of manned exploration and none of the cons.

The only downside I can see is speed of light lag. Latency.