re: Ed calims: "It turns out that using Moon based detectors rather than space based ones gives 6 months additional warning of inbound comets" This is BS!
A space based system can give a earlier detection and orbital path analysis than any Lunar based system! Because they can be placed where a Lunar or Earth based system cannot see on the other side of the sun for example.
Even Daniel Mazanek acknowledges this point.
http://rasc.larc.nasa.gov/rasc_new/CAPS/CAPS_Concept_Summary.pdf