RedShoe

the reason you hear two booms is because the nose of the shuttle and the tail break the sound barrier, just about second apart from each other.

I read that if you could travel just behind it, at the same speed, that you would hear a series of booms, like a giant machine gun.

since we are on the ground, (and not traveling at the speed of sound) we only hear one boom. Or if it's the space shuttle, you hear two.

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