Randy'sRocketShop
Member
- Joined
- Jan 24, 2013
- Messages
- 19
- Reaction score
- 0
Hey everyone.
I was watching the latest Soyuz launch two nights ago and noticed that just after the engines startup, but before liftoff, that the rocket rocks or tilts to the side and then swings back, basically doing about 1.5 or 2.5 oscillations as far as I could see. The oscillations damped out until the moment of liftoff. I was curious, so I looked back at a few older Soyuz launches and noticed basically the same phenomenon. Does anyone know anything about this? I would assume this is due to a staged engine startup of the four axially-mounted boosters. I know Space Shuttle started each of its three main engines a few milliseconds apart so that the entire force of engine startup was a little less jarring to the vehicle. Could it be the same thing with Soyuz, that a staged engine startup causes an initial sideways thrust imbalance that causes the stack to tilt to the side?
[YOUTUBE][video=youtube;Q_8VF7knp8E]Launch Video[/video][/YOUTUBE]
Thanks for any insight anyone has!
I was watching the latest Soyuz launch two nights ago and noticed that just after the engines startup, but before liftoff, that the rocket rocks or tilts to the side and then swings back, basically doing about 1.5 or 2.5 oscillations as far as I could see. The oscillations damped out until the moment of liftoff. I was curious, so I looked back at a few older Soyuz launches and noticed basically the same phenomenon. Does anyone know anything about this? I would assume this is due to a staged engine startup of the four axially-mounted boosters. I know Space Shuttle started each of its three main engines a few milliseconds apart so that the entire force of engine startup was a little less jarring to the vehicle. Could it be the same thing with Soyuz, that a staged engine startup causes an initial sideways thrust imbalance that causes the stack to tilt to the side?
[YOUTUBE][video=youtube;Q_8VF7knp8E]Launch Video[/video][/YOUTUBE]
Thanks for any insight anyone has!