This forum says "anything goes," so here goes....
“Good luck and Godspeed from the launch crew,” Paul Donnelly called out on his microphone, and Armstrong, from three and a half miles away answered, “Thank you very much.” Quietly, he added, “We know it’ll be a good flight.” There was confidence between them, the confidence of missionaries, the very air of messianic love - that love which, like Robert Frost's cube of ice, traveled on its melting.
Automatic sequence, and the members of the launch team stood at their dials looking for red-line values, looking for some last crisis or betrayal, some silent scream of the needle across the red line. The sequence was automatic, but the men were still considered more trustworthy than the machines themselves: the last control, the control above all others was a manual abort. Automatic or no, there was still the psychology of machines to be feared; so, man was still entitled to have the final say if some event which was incomprehensible to the machines occurred, and someone human must decide if the mission proceeded or stopped. On went the sequence. The gas generator valves in the base of Saturn V now closed on command, the main fuel valves from the Mobile Launcher shut off, the Emergency Detection System was activated in every circuit, the exhaust igniters came forward, the explosives for a destruct in midair were made potential, the hydraulic pressure in all systems were checked at once - OK; the voltage in all systems - OK; Instrument Unit ready for firing - OK; check-out valves in ground return position - OK; ...OK; ...OK: ... Oxidizer tanks in the upper stages now pressurized. Transfer to internal power on entire spacecraft. Astronauts report in. They are GO. The guidance system for controlling the ship in flight is now on full internal power. Seconds go by. Fifteen seconds to lift-off. Twelve seconds. The swing-arms begin to pull away. Five hundred volts pass through a cable still attached by its umbilical and goes into the bowels of the rocket to ignite the turbopump exhaust gases which burn the igniter links which trigger an electrical signal to open a four-way valve which opens the main Lox valves and propellants flow into the combuster. In seventeen separate split-second steps are gases ignited into fires which ignite other gases whose exhaust pressures open giant valves which release the orifice in the main tanks and on the fire of other fires are the rocket engines lit.
Eight and nine-tenth seconds before lift-off, the first flames burst out of the base of the rocket motors and vault dawn a concrete flame trench on the pad, a trench fifty-eight feet wide and forty-two feet deep. At its center is a cusp of metal concave on both slopes, a flame deflector forty-odd feet high and one million three hundred thousand pounds in weight. It receives all of the fury of the heat and blast as the five engines of the first stage build up in nine seconds to their seven and a half million pounds of thrust. Refractory concrete, volcanic ash, and calcium aluminate are the heat-protective skin for this flame deflector, which proceeds to divide the fires and send them away on each side down the trench to break into open air a hundred feet away on either side. Nozzles in the walls of the flame trench spew thousands of gallons of water a minute to cool the deflector, fifty thousand gallons a minute pour over the Mobile Launcher as the spaceship goes up, steam and smoke worthy of a volcano rise into the sky.
But for the moment the spaceship does not move. Four giant hold-down arms large as flying buttresses hold to a ring at the base of Saturn V while the thrust of the motors builds up in the nine seconds, reaches in thrust equal to the weight of the rocket. Does the rocket weigh six million, four hundred and eighty-four thousand, two hundred and eighty pounds? Now the thrust goes up, the flames pour out, now the thrust is four million, five million, six million, an extra million pounds of thrust each instant as those thousands of gallons of fuel rush every second to the motors, now it balances at six million, four hundred and eighty-four thousand, two hundred and eighty pounds. The bulk of Apollo-Saturn is in the balance on the pad. Come, you could now levitate it with a finger, but for the hold down arms. Now in the next second and the next, the thrust is up to full launch, to seven and a half million pounds, more, more than one million pounds of surplus force is now ready to push upward. And still the rocket is restrained. The hold down arms, large as buttresses, still retain the ship for two more seconds before lift-off. The last check-outs race through the automatic sequence and GO comes back; and the hold-down arms - what engineering in those giants! - pull back, and Apollo-Saturn rises inch by inch, then foot by foot, slowly, story by story, swing-arm by swing-arm, the swing-arms pulling back in the last five seconds, the last two seconds, umbilicals snapping back, slowly Apollo-Saturn climbs up the length of the Mobile Launcher, the flames of apocalypse no more than the sparks of its chariot, and spectators cry, "Go, baby, go!"
~excerpt from Of a Fire on the Moon,
Part II "Apollo"
Chapter 1 "The Psychology of Machines"
By Norman Mailer