(last value speed in mph)
11:26:46 AM...T+00:00...LAUNCH
11:26:57 AM...T+00:11...START ROLL MANEUVER.........................927
11:27:04 AM...T+00:18...END ROLL MANEUVER.........................1,002
11:27:18 AM...T+00:32...START THROTTLE DOWN (72%).................1,200
11:27:35 AM...T+00:49...START THROTTLE UP (104.5%)................1,432
11:27:47 AM...T+01:01...MAX Q (744 psf)...........................1,650
11:28:49 AM...T+02:03...SRB STAGING...............................3,627
11:28:59 AM...T+02:13...START OMS ASSIST (1:23 duration)..........3,743
927mph in 11s - talk about going places!
Those figures have to be taken in context:
That mph-value is an inertial speed. It's the speed of the Orbiter's (STS') center of mass rotating around Earth's center. Hence the inertial velocity of 914mph at standstill at T-00s.
Was the launchpad at either pole, the inertial velocity would be 0mph.
It's at maximum at the Equator - for obvious reasons.
The actual (aerodynamic/ relative to Earth's surface) velocities are given in the upper table as "velocity (e)".
That gives us 126mph after T+10s, which is a whole lot more reasonable.