What Causes the Space Shuttle Twang?

You’d think watching a massive spaceship wobble right before liftoff would be cause for panic, but nope, it’s totally normal. This groovy little dance move, affectionately called the Space Shuttle Twang, happens because at T-minus 6.6 seconds, the main engines ignite. Since they’re conveniently located at the bottom, this ignition creates a rotational force, causing the whole launch stack to tip forward a few degrees. Just when you’re about to lose your cool, the stack bounces back to its original position, and then BAM! The solid rocket boosters light up, and it’s liftoff time.

You’d think this dramatic sway could cause some concern, but NASA’s engineers were like, “Yep, that’s normal. We got this.”