Back in 2009 we heard the first of this, but it has become more of a priority now that a a manned mission to Mars is being considered. The problem of the radiation that astronauts have to deal with in a mission to the moon while troublesome becomes far greater when going to Mars. Having to do a spacewalk to fine tune something on the ship, replace some shields etc. could be catastrophic. A solar flare or such an event that could put the levels too high for too long a period of time. Enter the space robots. (cue cool super hero music)
Long term exposure to radiation is going to occur, even inside the space ship. From the flashes of light that seem to appear constantly behind the eyelids, to damaging atoms in the human bodies cells leading to everything from cataracts to cancer, heart disease, brain damage, or even damage to the central nervous system. Diet (anti-oxidants) and many other things are being considered, but those are mere bandaids and the greatest risk is outside the ship. This is when NASA would like to use robots. They have been used to assemble the tools necessary or prep the area on the ship to be worked on, basically acting as an assistant to the astronaut. Now the astronaut can exit the space ship for a much shorter period of time. Yes, some risk still exists, but not as great.
Now, in case this sounds a bit to SciFi to you, consider that aboard the International Space-station is R2, a robot developed by General Motors in conjunction with NASA. R2 is a permanent resident of ISS. R2 consists of a head, a torso, and two arms. His missions are specific to inside the space laboratory, but remember, baby steps. There are still some details to work out as far as the protection for R2 if outside the space station. Seems radiation and the elements, the micro-gravity, all are road-blocks.