Many people believe that the threat from having multiple sattelites armed with nuclear warheads orbitting the Earth would be far greater than the threat of an impact event. Perhaps if the sattelites were put in orbit around the Moon, though. That way, noone is worried that the program is just a trick to get the nukes in orbit and then fire on an enemy quickly enough to avoid a counter-strike. Any hostile move with the weapons would take days to reach Earth; plenty of time to react. Any accidental decay of orbit will be falling on the surface of the Moon, not the Earth.
Launch is still a problem. Final assembly, as well as refinement of radioactive materials should be done at a lunar base, so no refined radioactive materials would be exposed to the risks of launch. Lunar orbit would also give an advantage in kenetic state, allowing a shorter time-to intercept.