RE: Excitement grows.16 May 2019 20:19
NASA
T-minus 2 minutes
At this point, the shuttle's commander will advise his or her crewmates to close the visors of their launch and entry suits. In these final minutes leading up to launch, the Ground Launch Sequencer is still in automatic control of the countdown.
T-minus 31 seconds
At this moment in the countdown, if there are no technical issues, the "go" command will be given for "auto sequence start," which means that the Ground Launch Sequencer will hand off primary control of the countdown to the shuttle's onboard computers.
T-minus 16 seconds
Now, the sound suppression water system at the launch pad will be activated to protect the shuttle and its payloads from being damaged by the strong acoustical energy during liftoff. Water is stored in massive tanks on the northeast side of the launch pad and is released just prior to the ignition of the shuttle's main engines. Nine seconds after liftoff, the water suppression system's peak flow rate is 900,000 gallons per minute.
T-minus 6 seconds
Justprior to this moment, if everything is functioning as it should, the commandwill be given to start the space shuttle's main engines. Beginning at the T-minus6 second mark, each of the three main engines will be ignited and roar to life.
T-minus 0 seconds
The solid rocket boosters will be ignited, and the bolts that have secured the shuttle to the ground in the last six seconds of the countdown are explosively released, allowing the orbiter to rocket into the sky. Once this happens, we have liftoff!
GLA ??