Ignition of the three RS-25 main engines was sensed as a sharp increase in noise. The stack rocked "downwards" (towards the crew's feet), then back up to the vertical, at which point both Solid Rocket Boosters (SRBs) ignited. Crippen likened lift-off to a "steam catapult shot" (such as when an aircraft is launched from an aircraft carrier). The stack's combined northwards translation and climb above the launch tower's lightning rod were readily apparent to Young. After clearing the tower the stack began a right roll (until the +Z axis or vertical fin pointed) to a launch azimuth of 067° True (in order to achieve an orbital inclination of 40.3°), and pitched to a "heads down" attitude (to reduce loading on the wings). Simultaneously control was passed from the launch team in Florida to Flight Director Neil Hutchinson's Silver team in Flight Control Room 1 (FCR 1) in Texas with astronaut Dan Brandenstein as their CAPCOM.