Pushing Ares 1-X Around (Video)

Rock-a-bye Rocket (NASA, Ares I-X, 9/2/09)
“During the testing, vibrations were mechanically introduced into the rocket by four hydraulic shakers simulating the same kind of vibrations expected during flight so the effects could be monitored. A sway of the vehicle was then manually introduced (with a little help from Mission Manager, Bob Ess and Deputy Mission Manager Steve Davis) to create a lateral, back and forth motion so the team could measure how the rocket reacts.”