Astronomers have known for years that NEO's (Near Earth Objects) pose a serious threat to humanity (Tunguska 1908). Small NEO's are also a problem (Chelyabinsk 2013) We need a simple policy in place to safeguard against a possible disaster: the "detect and redirect" program.
This program would build multiple NEO detecting telescopes near as many universities as fiscally possible. Physics and astronomy faculty at each university would be in charge of maintaining them (reporting problems, etc) in exchange for research time on the machines. NASA would conduct NEO searches the rest of the time remotely.
The redirect program would first design and build a kinetic impact device powered by a chemical rocket. Later projects could include ion, fission, and fusion (etc) propulsion prototypes.