The sonic boom comes when it reenters the atmosphere. I grew up 20 miles from edwards afb. Heard it all the time, now i live where it launches from , and have never seen it from less than 200 miles. One of these days ill get down south and catch a launch. I can say though ,i have seen it piggyback on a 747 though, thats an odd thing too see flying over. I will say i am fortunate enough too have lived between edwards, and vandenburg afb, so ive witnessed all kinds of strange things flying in the night sky.Good on you for taking the time in life too enjoy one of mans greatest accomplishments!