Not only is this going to shed light on the makeup of comets and perhaps the early solar system, this experiment proved once and for all the ability of the United States protect the planet from spaceborne threats.
You misspelled irrelevant.
I would like you to elaborate and explain why it's important for you, to know what comets and the early solar system are made from, and how this relates to you in your everyday life. I'm sorry, but all this experiment proves is, that we can hit an object the size of Manhatten in space. It does not prove once and for all that the U.S. can protect the planet from spaceborne threats.
You left out the word "to" between the words States and protect.